mediaview: Mount ARC documents provider file system volumes.

New media view volumes are added to chromeos::VolumeManager so that they are
available to Files.app. UI patches are coming later, so at this point it looks like
unusable unknown volumes appear in Files.app. To hide them from users for now,
the feature is guarded with base::FeatureList. Once UI is ready I will make them
enabled by default.

BUG=chromium:671511
TEST=New (unusable) volumes are shown with --enable-features=ArcMediaView
TEST=Media views work with local pending UI patches

Review-Url: https://codereview.chromium.org/2580303002
Cr-Commit-Position: refs/heads/master@{#443205}

chrome/browser/chromeos/BUILD.gn

@@ -263,6 +263,8 @@ source_set("chromeos") {
     "arc/fileapi/arc_file_system_instance_util.h",
     "arc/fileapi/arc_file_system_service.cc",
     "arc/fileapi/arc_file_system_service.h",
+    "arc/fileapi/arc_media_view_util.cc",
+    "arc/fileapi/arc_media_view_util.h",
     "arc/intent_helper/arc_external_protocol_dialog.cc",
     "arc/intent_helper/arc_external_protocol_dialog.h",
     "arc/intent_helper/arc_navigation_throttle.cc",

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.cc

@@ -14,11 +14,48 @@
 
 namespace arc {
 
+// This is based on net/base/escape.cc: net::(anonymous namespace)::Escape.
+// TODO(nya): Consider consolidating this function with EscapeFileSystemId() in
+// chrome/browser/chromeos/file_system_provider/mount_path_util.cc.
+// This version differs from the other one in the point that dots are not always
+// escaped because authorities often contain harmless dots.
+std::string EscapePathComponent(const std::string& name) {
+  std::string escaped;
+  // Escape dots only when they forms a special file name.
+  if (name == "." || name == "..") {
+    base::ReplaceChars(name, ".", "%2E", &escaped);
+    return escaped;
+  }
+  // Escape % and / only.
+  for (size_t i = 0; i < name.size(); ++i) {
+    const char c = name[i];
+    if (c == '%' || c == '/')
+      base::StringAppendF(&escaped, "%%%02X", c);
+    else
+      escaped.push_back(c);
+  }
+  return escaped;
+}
+
+std::string UnescapePathComponent(const std::string& escaped) {
+  return net::UnescapeURLComponent(
+      escaped, net::UnescapeRule::PATH_SEPARATORS |
+                   net::UnescapeRule::URL_SPECIAL_CHARS_EXCEPT_PATH_SEPARATORS);
+}
+
 const char kDocumentsProviderMountPointName[] = "arc-documents-provider";
 const base::FilePath::CharType kDocumentsProviderMountPointPath[] =
     "/special/arc-documents-provider";
 const char kAndroidDirectoryMimeType[] = "vnd.android.document/directory";
 
+base::FilePath GetDocumentsProviderMountPath(
+    const std::string& authority,
+    const std::string& root_document_id) {
+  return base::FilePath(kDocumentsProviderMountPointPath)
+      .Append(EscapePathComponent(authority))
+      .Append(EscapePathComponent(root_document_id));
+}
+
 bool ParseDocumentsProviderUrl(const storage::FileSystemURL& url,
                                std::string* authority,
                                std::string* root_document_id,
@@ -39,12 +76,11 @@ bool ParseDocumentsProviderUrl(const storage::FileSystemURL& url,
   if (components.size() < 5)
     return false;
 
-  *authority = components[3];
-  *root_document_id = components[4];
+  *authority = UnescapePathComponent(components[3]);
+  *root_document_id = UnescapePathComponent(components[4]);
 
-  base::FilePath root_path = base::FilePath(kDocumentsProviderMountPointPath)
-                                 .Append(*authority)
-                                 .Append(*root_document_id);
+  base::FilePath root_path =
+      GetDocumentsProviderMountPath(*authority, *root_document_id);
   // Special case: AppendRelativePath() fails for identical paths.
   if (url_path_stripped == root_path) {
     path->clear();

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h

@@ -29,7 +29,28 @@ extern const base::FilePath::CharType kDocumentsProviderMountPointPath[];
 // Defined as DocumentsContract.Document.MIME_TYPE_DIR in Android.
 extern const char kAndroidDirectoryMimeType[];
 
+// Escapes a string so it can be used as a file/directory name.
+// [%/.] are escaped with percent-encoding.
+// NOTE: This function is visible only for unit testing. Usually you should not
+// call this function directly.
+std::string EscapePathComponent(const std::string& name);
+
+// Unescapes a string escaped by EscapePathComponent().
+// NOTE: This function is visible only for unit testing. Usually you should not
+// call this function directly.
+std::string UnescapePathComponent(const std::string& escaped);
+
+// Returns the path of a directory where the specified DocumentsProvider is
+// mounted.
+// Appropriate escaping is done to embed |authority| and |root_document_id| in
+// a file path.
+base::FilePath GetDocumentsProviderMountPath(
+    const std::string& authority,
+    const std::string& root_document_id);
+
 // Parses a FileSystemURL pointing to ARC documents provider file system.
+// Appropriate unescaping is done to extract |authority| and |root_document_id|
+// from |url|.
 // On success, true is returned. All arguments must not be nullptr.
 bool ParseDocumentsProviderUrl(const storage::FileSystemURL& url,
                                std::string* authority,

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util_unittest.cc

@@ -12,6 +12,45 @@ namespace arc {
 
 namespace {
 
+TEST(ArcDocumentsProviderUtilTest, EscapePathComponent) {
+  EXPECT_EQ("", EscapePathComponent(""));
+  EXPECT_EQ("%2E", EscapePathComponent("."));
+  EXPECT_EQ("%2E%2E", EscapePathComponent(".."));
+  EXPECT_EQ("...", EscapePathComponent("..."));
+  EXPECT_EQ("example.com", EscapePathComponent("example.com"));
+  EXPECT_EQ("%2F%2F%2F", EscapePathComponent("///"));
+  EXPECT_EQ("100%25", EscapePathComponent("100%"));
+  EXPECT_EQ("a b", EscapePathComponent("a b"));
+  EXPECT_EQ("ねこ", EscapePathComponent("ねこ"));
+}
+
+TEST(ArcDocumentsProviderUtilTest, UnescapePathComponent) {
+  EXPECT_EQ("", UnescapePathComponent(""));
+  EXPECT_EQ(".", UnescapePathComponent("%2E"));
+  EXPECT_EQ("..", UnescapePathComponent("%2E%2E"));
+  EXPECT_EQ("...", UnescapePathComponent("..."));
+  EXPECT_EQ("example.com", UnescapePathComponent("example.com"));
+  EXPECT_EQ("///", UnescapePathComponent("%2F%2F%2F"));
+  EXPECT_EQ("100%", UnescapePathComponent("100%25"));
+  EXPECT_EQ("a b", UnescapePathComponent("a b"));
+  EXPECT_EQ("ねこ", UnescapePathComponent("ねこ"));
+}
+
+TEST(ArcDocumentsProviderUtilTest, GetDocumentsProviderMountPath) {
+  EXPECT_EQ("/special/arc-documents-provider/authority/document_id",
+            GetDocumentsProviderMountPath("authority", "document_id").value());
+  EXPECT_EQ("/special/arc-documents-provider/a b/a b",
+            GetDocumentsProviderMountPath("a b", "a b").value());
+  EXPECT_EQ("/special/arc-documents-provider/a%2Fb/a%2Fb",
+            GetDocumentsProviderMountPath("a/b", "a/b").value());
+  EXPECT_EQ("/special/arc-documents-provider/%2E/%2E",
+            GetDocumentsProviderMountPath(".", ".").value());
+  EXPECT_EQ("/special/arc-documents-provider/%2E%2E/%2E%2E",
+            GetDocumentsProviderMountPath("..", "..").value());
+  EXPECT_EQ("/special/arc-documents-provider/.../...",
+            GetDocumentsProviderMountPath("...", "...").value());
+}
+
 TEST(ArcDocumentsProviderUtilTest, ParseDocumentsProviderUrl) {
   std::string authority;
   std::string root_document_id;
@@ -118,6 +157,22 @@ TEST(ArcDocumentsProviderUtilTest, ParseDocumentsProviderUrlInvalidPath) {
       &authority, &root_document_id, &path));
 }
 
+TEST(ArcDocumentsProviderUtilTest, ParseDocumentsProviderUrlUnescape) {
+  std::string authority;
+  std::string root_document_id;
+  base::FilePath path;
+
+  EXPECT_TRUE(ParseDocumentsProviderUrl(
+      storage::FileSystemURL::CreateForTest(
+          GURL(), storage::kFileSystemTypeArcDocumentsProvider,
+          base::FilePath(
+              "/special/arc-documents-provider/cats/ro%2Fot/home/calico.jpg")),
+      &authority, &root_document_id, &path));
+  EXPECT_EQ("cats", authority);
+  EXPECT_EQ("ro/ot", root_document_id);
+  EXPECT_EQ(FILE_PATH_LITERAL("home/calico.jpg"), path.value());
+}
+
 TEST(ArcDocumentsProviderUtilTest, ParseDocumentsProviderUrlUtf8) {
   std::string authority;
   std::string root_document_id;
@@ -135,8 +190,13 @@ TEST(ArcDocumentsProviderUtilTest, ParseDocumentsProviderUrlUtf8) {
 }
 
 TEST(ArcDocumentsProviderUtilTest, BuildDocumentUrl) {
-  EXPECT_EQ("content://Cat%20Provider/document/C%2B%2B",
-            BuildDocumentUrl("Cat Provider", "C++").spec());
+  EXPECT_EQ("content://authority/document/document_id",
+            BuildDocumentUrl("authority", "document_id").spec());
+  EXPECT_EQ("content://a%20b/document/a%20b",
+            BuildDocumentUrl("a b", "a b").spec());
+  EXPECT_EQ("content://a%2Fb/document/a%2Fb",
+            BuildDocumentUrl("a/b", "a/b").spec());
+  EXPECT_EQ("content://../document/..", BuildDocumentUrl("..", "..").spec());
 }
 
 }  // namespace

chrome/browser/chromeos/arc/fileapi/arc_file_system_service.cc

@@ -8,6 +8,7 @@
 #include "chrome/browser/chromeos/arc/fileapi/arc_content_file_system_url_util.h"
 #include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/file_system/arc_file_system_observer.h"
 #include "content/public/browser/browser_thread.h"
 #include "storage/browser/fileapi/external_mount_points.h"
 
@@ -15,6 +16,10 @@ using content::BrowserThread;
 
 namespace arc {
 
+// static
+const char ArcFileSystemService::kArcServiceName[] =
+    "arc::ArcFileSystemService";
+
 ArcFileSystemService::ArcFileSystemService(ArcBridgeService* bridge_service)
     : ArcService(bridge_service) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
@@ -31,11 +36,15 @@ ArcFileSystemService::ArcFileSystemService(ArcBridgeService* bridge_service)
       storage::kFileSystemTypeArcDocumentsProvider,
       storage::FileSystemMountOption(),
       base::FilePath(kDocumentsProviderMountPointPath));
+
+  arc_bridge_service()->file_system()->AddObserver(this);
 }
 
 ArcFileSystemService::~ArcFileSystemService() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
+  arc_bridge_service()->file_system()->RemoveObserver(this);
+
   storage::ExternalMountPoints* mount_points =
       storage::ExternalMountPoints::GetSystemInstance();
 
@@ -43,4 +52,22 @@ ArcFileSystemService::~ArcFileSystemService() {
   mount_points->RevokeFileSystem(kDocumentsProviderMountPointPath);
 }
 
+void ArcFileSystemService::AddObserver(ArcFileSystemObserver* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void ArcFileSystemService::RemoveObserver(ArcFileSystemObserver* observer) {
+  observer_list_.RemoveObserver(observer);
+}
+
+void ArcFileSystemService::OnInstanceReady() {
+  for (auto& observer : observer_list_)
+    observer.OnFileSystemsReady();
+}
+
+void ArcFileSystemService::OnInstanceClosed() {
+  for (auto& observer : observer_list_)
+    observer.OnFileSystemsClosed();
+}
+
 }  // namespace arc

chrome/browser/chromeos/arc/fileapi/arc_file_system_service.h

@@ -6,19 +6,37 @@
 #define CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_FILE_SYSTEM_SERVICE_H_
 
 #include "base/macros.h"
+#include "base/observer_list.h"
 #include "components/arc/arc_service.h"
+#include "components/arc/common/file_system.mojom.h"
+#include "components/arc/instance_holder.h"
 
 namespace arc {
 
 class ArcBridgeService;
+class ArcFileSystemObserver;
 
 // ArcFileSystemService registers ARC file systems to the system.
-class ArcFileSystemService : public ArcService {
+class ArcFileSystemService
+    : public ArcService,
+      public InstanceHolder<mojom::FileSystemInstance>::Observer {
  public:
   explicit ArcFileSystemService(ArcBridgeService* bridge_service);
   ~ArcFileSystemService() override;
 
+  void AddObserver(ArcFileSystemObserver* observer);
+  void RemoveObserver(ArcFileSystemObserver* observer);
+
+  // InstanceHolder<mojom::FileSystemInstance>::Observer overrides:
+  void OnInstanceReady() override;
+  void OnInstanceClosed() override;
+
+  // For supporting ArcServiceManager::GetService<T>().
+  static const char kArcServiceName[];
+
  private:
+  base::ObserverList<ArcFileSystemObserver> observer_list_;
+
   DISALLOW_COPY_AND_ASSIGN(ArcFileSystemService);
 };
 

chrome/browser/chromeos/arc/fileapi/arc_media_view_util.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/arc/fileapi/arc_media_view_util.h"
+
+namespace arc {
+
+namespace {
+
+constexpr char kMediaViewVolumeIdPrefix[] = "media_view:";
+
+}  // namespace
+
+const base::Feature kMediaViewFeature{"ArcMediaView",
+                                      base::FEATURE_DISABLED_BY_DEFAULT};
+
+const char kMediaDocumentsProviderAuthority[] =
+    "com.android.providers.media.documents";
+
+const char kImagesRootDocumentId[] = "images_root";
+const char kVideosRootDocumentId[] = "videos_root";
+const char kAudioRootDocumentId[] = "audio_root";
+
+std::string GetMediaViewVolumeId(const std::string& root_document_id) {
+  return std::string(kMediaViewVolumeIdPrefix) + root_document_id;
+}
+
+}  // namespace arc

chrome/browser/chromeos/arc/fileapi/arc_media_view_util.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Utilities for ARC Media View.
+
+#ifndef CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_MEDIA_VIEW_UTIL_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_MEDIA_VIEW_UTIL_H_
+
+#include <string>
+
+#include "base/feature_list.h"
+
+namespace arc {
+
+// base::FeatureList feature for ARC media view.
+extern const base::Feature kMediaViewFeature;
+
+// Authority of MediaDocumentsProvider in Android.
+extern const char kMediaDocumentsProviderAuthority[];
+
+// Document IDs of file system roots in MediaDocumentsProvider.
+extern const char kImagesRootDocumentId[];
+extern const char kVideosRootDocumentId[];
+extern const char kAudioRootDocumentId[];
+
+// Returns an ID of a Media View volume.
+std::string GetMediaViewVolumeId(const std::string& root_document_id);
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_FILEAPI_ARC_MEDIA_VIEW_UTIL_H_

chrome/browser/chromeos/extensions/file_manager/private_api_util.cc

@@ -242,6 +242,10 @@ void VolumeToVolumeMetadata(
     case VOLUME_TYPE_MTP:
       volume_metadata->volume_type = file_manager_private::VOLUME_TYPE_MTP;
       break;
+    case VOLUME_TYPE_MEDIA_VIEW:
+      volume_metadata->volume_type =
+          file_manager_private::VOLUME_TYPE_MEDIA_VIEW;
+      break;
     case VOLUME_TYPE_TESTING:
       volume_metadata->volume_type =
           file_manager_private::VOLUME_TYPE_TESTING;

chrome/browser/chromeos/file_manager/volume_manager.cc

@@ -9,6 +9,7 @@
 
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/feature_list.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
@@ -16,6 +17,10 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/chromeos/arc/arc_session_manager.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_file_system_service.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_media_view_util.h"
 #include "chrome/browser/chromeos/drive/drive_integration_service.h"
 #include "chrome/browser/chromeos/drive/file_system_util.h"
 #include "chrome/browser/chromeos/file_manager/path_util.h"
@@ -29,6 +34,7 @@
 #include "chrome/common/pref_names.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/disks/disk_mount_manager.h"
+#include "components/arc/arc_service_manager.h"
 #include "components/drive/chromeos/file_system_interface.h"
 #include "components/drive/file_system_core_util.h"
 #include "components/prefs/pref_service.h"
@@ -111,6 +117,8 @@ std::string VolumeTypeToString(VolumeType type) {
       return "provided";
     case VOLUME_TYPE_MTP:
       return "mtp";
+    case VOLUME_TYPE_MEDIA_VIEW:
+      return "media_view";
     case VOLUME_TYPE_TESTING:
       return "testing";
     case NUM_VOLUME_TYPE:
@@ -270,6 +278,22 @@ Volume* Volume::CreateForMTP(const base::FilePath& mount_path,
   return volume;
 }
 
+// static
+Volume* Volume::CreateForMediaView(const std::string& root_document_id) {
+  Volume* const volume = new Volume;
+  volume->type_ = VOLUME_TYPE_MEDIA_VIEW;
+  volume->device_type_ = chromeos::DEVICE_TYPE_UNKNOWN;
+  volume->source_ = SOURCE_SYSTEM;
+  volume->mount_path_ = arc::GetDocumentsProviderMountPath(
+      arc::kMediaDocumentsProviderAuthority, root_document_id);
+  volume->mount_condition_ = chromeos::disks::MOUNT_CONDITION_NONE;
+  volume->volume_label_ = root_document_id;
+  volume->is_read_only_ = true;
+  volume->watchable_ = false;
+  volume->volume_id_ = arc::GetMediaViewVolumeId(root_document_id);
+  return volume;
+}
+
 // static
 Volume* Volume::CreateForTesting(const base::FilePath& path,
                                  VolumeType volume_type,
@@ -382,6 +406,13 @@ void VolumeManager::Initialize() {
         base::Bind(&VolumeManager::OnStorageMonitorInitialized,
                    weak_ptr_factory_.GetWeakPtr()));
   }
+
+  // Subscribe to ARC file system events.
+  if (base::FeatureList::IsEnabled(arc::kMediaViewFeature) &&
+      arc::ArcSessionManager::IsAllowedForProfile(profile_)) {
+    arc::ArcServiceManager::GetGlobalService<arc::ArcFileSystemService>()
+        ->AddObserver(this);
+  }
 }
 
 void VolumeManager::Shutdown() {
@@ -398,6 +429,17 @@ void VolumeManager::Shutdown() {
 
   if (file_system_provider_service_)
     file_system_provider_service_->RemoveObserver(this);
+
+  // Unsubscribe from ARC file system events.
+  if (base::FeatureList::IsEnabled(arc::kMediaViewFeature) &&
+      arc::ArcSessionManager::IsAllowedForProfile(profile_)) {
+    arc::ArcFileSystemService* file_system_service =
+        arc::ArcServiceManager::GetGlobalService<arc::ArcFileSystemService>();
+    // TODO(crbug.com/672829): We need nullptr check here because
+    // ArcServiceManager may or may not be alive at this point.
+    if (file_system_service)
+      file_system_service->RemoveObserver(this);
+  }
 }
 
 void VolumeManager::AddObserver(VolumeManagerObserver* observer) {
@@ -702,6 +744,38 @@ void VolumeManager::OnExternalStorageDisabledChangedUnmountCallback(
           weak_ptr_factory_.GetWeakPtr()));
 }
 
+void VolumeManager::OnFileSystemsReady() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(base::FeatureList::IsEnabled(arc::kMediaViewFeature));
+  DCHECK(arc::ArcSessionManager::IsAllowedForProfile(profile_));
+
+  DoMountEvent(chromeos::MOUNT_ERROR_NONE,
+               linked_ptr<Volume>(
+                   Volume::CreateForMediaView(arc::kImagesRootDocumentId)));
+  DoMountEvent(chromeos::MOUNT_ERROR_NONE,
+               linked_ptr<Volume>(
+                   Volume::CreateForMediaView(arc::kVideosRootDocumentId)));
+  DoMountEvent(chromeos::MOUNT_ERROR_NONE,
+               linked_ptr<Volume>(
+                   Volume::CreateForMediaView(arc::kAudioRootDocumentId)));
+}
+
+void VolumeManager::OnFileSystemsClosed() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  DCHECK(base::FeatureList::IsEnabled(arc::kMediaViewFeature));
+  DCHECK(arc::ArcSessionManager::IsAllowedForProfile(profile_));
+
+  DoUnmountEvent(chromeos::MOUNT_ERROR_NONE,
+                 linked_ptr<Volume>(
+                     Volume::CreateForMediaView(arc::kImagesRootDocumentId)));
+  DoUnmountEvent(chromeos::MOUNT_ERROR_NONE,
+                 linked_ptr<Volume>(
+                     Volume::CreateForMediaView(arc::kVideosRootDocumentId)));
+  DoUnmountEvent(chromeos::MOUNT_ERROR_NONE,
+                 linked_ptr<Volume>(
+                     Volume::CreateForMediaView(arc::kAudioRootDocumentId)));
+}
+
 void VolumeManager::OnExternalStorageDisabledChanged() {
   // If the policy just got disabled we have to unmount every device currently
   // mounted. The opposite is fine - we can let the user re-plug their device to

chrome/browser/chromeos/file_manager/volume_manager.h

@@ -22,6 +22,7 @@
 #include "chrome/browser/chromeos/file_system_provider/service.h"
 #include "chromeos/dbus/cros_disks_client.h"
 #include "chromeos/disks/disk_mount_manager.h"
+#include "components/arc/file_system/arc_file_system_observer.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "components/storage_monitor/removable_storage_observer.h"
@@ -51,6 +52,7 @@ enum VolumeType {
   VOLUME_TYPE_MOUNTED_ARCHIVE_FILE,
   VOLUME_TYPE_PROVIDED,  // File system provided by the FileSystemProvider API.
   VOLUME_TYPE_MTP,
+  VOLUME_TYPE_MEDIA_VIEW,
   // The enum values must be kept in sync with FileManagerVolumeType in
   // tools/metrics/histograms/histograms.xml. Since enums for histograms are
   // append-only (for keeping the number consistent across versions), new values
@@ -90,6 +92,7 @@ class Volume : public base::SupportsWeakPtr<Volume> {
   static Volume* CreateForMTP(const base::FilePath& mount_path,
                               const std::string& label,
                               bool read_only);
+  static Volume* CreateForMediaView(const std::string& root_document_id);
   static Volume* CreateForTesting(const base::FilePath& path,
                                   VolumeType volume_type,
                                   chromeos::DeviceType device_type,
@@ -211,6 +214,7 @@ class Volume : public base::SupportsWeakPtr<Volume> {
 //   for a device).
 // - Mounted zip archives.
 class VolumeManager : public KeyedService,
+                      public arc::ArcFileSystemObserver,
                       public drive::DriveIntegrationServiceObserver,
                       public chromeos::disks::DiskMountManager::Observer,
                       public chromeos::file_system_provider::Observer,
@@ -297,6 +301,10 @@ class VolumeManager : public KeyedService,
           file_system_info,
       base::File::Error error) override;
 
+  // arc::ArcFileSystemObserver overrides.
+  void OnFileSystemsReady() override;
+  void OnFileSystemsClosed() override;
+
   // Called on change to kExternalStorageDisabled pref.
   void OnExternalStorageDisabledChanged();
 

chrome/browser/chromeos/fileapi/file_system_backend.cc

@@ -11,12 +11,14 @@
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "chrome/browser/chromeos/arc/fileapi/arc_documents_provider_util.h"
 #include "chrome/browser/chromeos/fileapi/file_access_permissions.h"
 #include "chrome/browser/chromeos/fileapi/file_system_backend_delegate.h"
 #include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
 #include "chrome/common/url_constants.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/dbus/cros_disks_client.h"
+#include "net/base/escape.h"
 #include "storage/browser/fileapi/async_file_util.h"
 #include "storage/browser/fileapi/external_mount_points.h"
 #include "storage/browser/fileapi/file_stream_reader.h"
@@ -26,6 +28,7 @@
 #include "storage/browser/fileapi/file_system_operation_context.h"
 #include "storage/browser/fileapi/file_system_url.h"
 #include "storage/common/fileapi/file_system_mount_option.h"
+#include "storage/common/fileapi/file_system_util.h"
 
 namespace chromeos {
 namespace {
@@ -156,6 +159,27 @@ void FileSystemBackend::ResolveURL(const storage::FileSystemURL& url,
     std::string inner_mount_name = components[1];
     root_url += inner_mount_name + "/";
     name = inner_mount_name;
+  } else if (id == arc::kDocumentsProviderMountPointName) {
+    // For ARC documents provider file system, volumes are mounted per document
+    // provider root, so we need to fix up |root_url| to point to an individual
+    // root.
+    std::string authority;
+    std::string root_document_id;
+    base::FilePath unused_path;
+    if (!arc::ParseDocumentsProviderUrl(url, &authority, &root_document_id,
+                                        &unused_path)) {
+      callback.Run(GURL(root_url), std::string(),
+                   base::File::FILE_ERROR_SECURITY);
+      return;
+    }
+    base::FilePath mount_path =
+        arc::GetDocumentsProviderMountPath(authority, root_document_id);
+    base::FilePath relative_mount_path;
+    base::FilePath(arc::kDocumentsProviderMountPointPath)
+        .AppendRelativePath(mount_path, &relative_mount_path);
+    root_url +=
+        net::EscapePath(storage::FilePathToString(relative_mount_path)) + "/";
+    name = authority + ":" + root_document_id;
   } else {
     name = id;
   }

chrome/common/extensions/api/file_manager_private.idl

@@ -9,7 +9,7 @@
 namespace fileManagerPrivate {
 // Type of the mounted volume.
 enum VolumeType { drive, downloads, removable, archive, provided, mtp,
-                  testing };
+                  media_view, testing };
 
 // Device type. Available if this is removable volume.
 enum DeviceType { usb, sd, optical, mobile, unknown };

components/arc/BUILD.gn

@@ -21,6 +21,7 @@ static_library("arc") {
     "clipboard/arc_clipboard_bridge.h",
     "crash_collector/arc_crash_collector_bridge.cc",
     "crash_collector/arc_crash_collector_bridge.h",
+    "file_system/arc_file_system_observer.h",
     "ime/arc_ime_bridge.h",
     "ime/arc_ime_bridge_impl.cc",
     "ime/arc_ime_bridge_impl.h",

components/arc/file_system/arc_file_system_observer.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_ARC_FILE_SYSTEM_ARC_FILE_SYSTEM_OBSERVER_H_
+#define COMPONENTS_ARC_FILE_SYSTEM_ARC_FILE_SYSTEM_OBSERVER_H_
+
+namespace arc {
+
+class ArcFileSystemObserver {
+ public:
+  virtual ~ArcFileSystemObserver() = default;
+
+  // Called when ARC file systems are ready.
+  virtual void OnFileSystemsReady() = 0;
+
+  // Called when ARC file systems are closed.
+  virtual void OnFileSystemsClosed() = 0;
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_ARC_FILE_SYSTEM_ARC_FILE_SYSTEM_OBSERVER_H_

third_party/closure_compiler/externs/file_manager_private.js

-// Copyright 2014 The Chromium Authors. All rights reserved.
+// Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// This file was generated by:
+//   tools/json_schema_compiler/compiler.py.
+// NOTE: The format of types has changed. 'FooType' is now
+//   'chrome.fileManagerPrivate.FooType'.
+// Please run the closure compiler before committing changes.
+// See https://chromium.googlesource.com/chromium/src/+/master/docs/closure_compilation.md
+
 /** @fileoverview Externs generated from namespace: fileManagerPrivate */
 
+/**
+ * @const
+ */
+chrome.fileManagerPrivate = {};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-VolumeType
+ */
+chrome.fileManagerPrivate.VolumeType = {
+  DRIVE: 'drive',
+  DOWNLOADS: 'downloads',
+  REMOVABLE: 'removable',
+  ARCHIVE: 'archive',
+  PROVIDED: 'provided',
+  MTP: 'mtp',
+  MEDIA_VIEW: 'media_view',
+  TESTING: 'testing',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DeviceType
+ */
+chrome.fileManagerPrivate.DeviceType = {
+  USB: 'usb',
+  SD: 'sd',
+  OPTICAL: 'optical',
+  MOBILE: 'mobile',
+  UNKNOWN: 'unknown',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-MountCondition
+ */
+chrome.fileManagerPrivate.MountCondition = {
+  UNKNOWN: 'unknown',
+  UNSUPPORTED: 'unsupported',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-MountContext
+ */
+chrome.fileManagerPrivate.MountContext = {
+  USER: 'user',
+  AUTO: 'auto',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-MountCompletedEventType
+ */
+chrome.fileManagerPrivate.MountCompletedEventType = {
+  MOUNT: 'mount',
+  UNMOUNT: 'unmount',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-MountCompletedStatus
+ */
+chrome.fileManagerPrivate.MountCompletedStatus = {
+  SUCCESS: 'success',
+  ERROR_UNKNOWN: 'error_unknown',
+  ERROR_INTERNAL: 'error_internal',
+  ERROR_INVALID_ARGUMENT: 'error_invalid_argument',
+  ERROR_INVALID_PATH: 'error_invalid_path',
+  ERROR_PATH_ALREADY_MOUNTED: 'error_path_already_mounted',
+  ERROR_PATH_NOT_MOUNTED: 'error_path_not_mounted',
+  ERROR_DIRECTORY_CREATION_FAILED: 'error_directory_creation_failed',
+  ERROR_INVALID_MOUNT_OPTIONS: 'error_invalid_mount_options',
+  ERROR_INVALID_UNMOUNT_OPTIONS: 'error_invalid_unmount_options',
+  ERROR_INSUFFICIENT_PERMISSIONS: 'error_insufficient_permissions',
+  ERROR_MOUNT_PROGRAM_NOT_FOUND: 'error_mount_program_not_found',
+  ERROR_MOUNT_PROGRAM_FAILED: 'error_mount_program_failed',
+  ERROR_INVALID_DEVICE_PATH: 'error_invalid_device_path',
+  ERROR_UNKNOWN_FILESYSTEM: 'error_unknown_filesystem',
+  ERROR_UNSUPPORTED_FILESYSTEM: 'error_unsupported_filesystem',
+  ERROR_INVALID_ARCHIVE: 'error_invalid_archive',
+  ERROR_AUTHENTICATION: 'error_authentication',
+  ERROR_PATH_UNMOUNTED: 'error_path_unmounted',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-TransferState
+ */
+chrome.fileManagerPrivate.TransferState = {
+  IN_PROGRESS: 'in_progress',
+  COMPLETED: 'completed',
+  FAILED: 'failed',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-TransferType
+ */
+chrome.fileManagerPrivate.TransferType = {
+  UPLOAD: 'upload',
+  DOWNLOAD: 'download',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-CopyProgressStatusType
+ */
+chrome.fileManagerPrivate.CopyProgressStatusType = {
+  BEGIN_COPY_ENTRY: 'begin_copy_entry',
+  END_COPY_ENTRY: 'end_copy_entry',
+  PROGRESS: 'progress',
+  SUCCESS: 'success',
+  ERROR: 'error',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-FileWatchEventType
+ */
+chrome.fileManagerPrivate.FileWatchEventType = {
+  CHANGED: 'changed',
+  ERROR: 'error',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-ChangeType
+ */
+chrome.fileManagerPrivate.ChangeType = {
+  ADD_OR_UPDATE: 'add_or_update',
+  DELETE: 'delete',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-SearchType
+ */
+chrome.fileManagerPrivate.SearchType = {
+  EXCLUDE_DIRECTORIES: 'EXCLUDE_DIRECTORIES',
+  SHARED_WITH_ME: 'SHARED_WITH_ME',
+  OFFLINE: 'OFFLINE',
+  ALL: 'ALL',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-ZoomOperationType
+ */
+chrome.fileManagerPrivate.ZoomOperationType = {
+  IN: 'in',
+  OUT: 'out',
+  RESET: 'reset',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-InspectionType
+ */
+chrome.fileManagerPrivate.InspectionType = {
+  NORMAL: 'normal',
+  CONSOLE: 'console',
+  ELEMENT: 'element',
+  BACKGROUND: 'background',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DeviceEventType
+ */
+chrome.fileManagerPrivate.DeviceEventType = {
+  DISABLED: 'disabled',
+  REMOVED: 'removed',
+  HARD_UNPLUGGED: 'hard_unplugged',
+  FORMAT_START: 'format_start',
+  FORMAT_SUCCESS: 'format_success',
+  FORMAT_FAIL: 'format_fail',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DriveSyncErrorType
+ */
+chrome.fileManagerPrivate.DriveSyncErrorType = {
+  DELETE_WITHOUT_PERMISSION: 'delete_without_permission',
+  SERVICE_UNAVAILABLE: 'service_unavailable',
+  NO_SERVER_SPACE: 'no_server_space',
+  MISC: 'misc',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-TaskResult
+ */
+chrome.fileManagerPrivate.TaskResult = {
+  OPENED: 'opened',
+  MESSAGE_SENT: 'message_sent',
+  FAILED: 'failed',
+  EMPTY: 'empty',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DriveShareType
+ */
+chrome.fileManagerPrivate.DriveShareType = {
+  CAN_EDIT: 'can_edit',
+  CAN_COMMENT: 'can_comment',
+  CAN_VIEW: 'can_view',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-EntryPropertyName
+ */
+chrome.fileManagerPrivate.EntryPropertyName = {
+  SIZE: 'size',
+  MODIFICATION_TIME: 'modificationTime',
+  THUMBNAIL_URL: 'thumbnailUrl',
+  CROPPED_THUMBNAIL_URL: 'croppedThumbnailUrl',
+  IMAGE_WIDTH: 'imageWidth',
+  IMAGE_HEIGHT: 'imageHeight',
+  IMAGE_ROTATION: 'imageRotation',
+  PINNED: 'pinned',
+  PRESENT: 'present',
+  HOSTED: 'hosted',
+  AVAILABLE_OFFLINE: 'availableOffline',
+  AVAILABLE_WHEN_METERED: 'availableWhenMetered',
+  DIRTY: 'dirty',
+  CUSTOM_ICON_URL: 'customIconUrl',
+  CONTENT_MIME_TYPE: 'contentMimeType',
+  SHARED_WITH_ME: 'sharedWithMe',
+  SHARED: 'shared',
+  STARRED: 'starred',
+  EXTERNAL_FILE_URL: 'externalFileUrl',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-EntryTagVisibility
+ */
+chrome.fileManagerPrivate.EntryTagVisibility = {
+  PRIVATE: 'private',
+  PUBLIC: 'public',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-Source
+ */
+chrome.fileManagerPrivate.Source = {
+  FILE: 'file',
+  DEVICE: 'device',
+  NETWORK: 'network',
+  SYSTEM: 'system',
+};
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-Verb
+ */
+chrome.fileManagerPrivate.Verb = {
+  OPEN_WITH: 'open_with',
+  ADD_TO: 'add_to',
+  PACK_WITH: 'pack_with',
+  SHARE_WITH: 'share_with',
+};
+
 /**
  * @typedef {{
  *   taskId: string,
  *   title: string,
+ *   verb: (!chrome.fileManagerPrivate.Verb|undefined),
  *   iconUrl: string,
- *   isDefault: boolean
+ *   isDefault: boolean,
+ *   isGenericFileHandler: boolean
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-FileTask
  */
-var FileTask;
+chrome.fileManagerPrivate.FileTask;
 
 /**
  * @typedef {{
@@ -20,31 +298,34 @@ var FileTask;
  *   modificationTime: (number|undefined),
  *   thumbnailUrl: (string|undefined),
  *   croppedThumbnailUrl: (string|undefined),
- *   externalFileUrl: (string|undefined),
  *   imageWidth: (number|undefined),
  *   imageHeight: (number|undefined),
  *   imageRotation: (number|undefined),
  *   pinned: (boolean|undefined),
  *   present: (boolean|undefined),
  *   hosted: (boolean|undefined),
- *   dirty: (boolean|undefined),
  *   availableOffline: (boolean|undefined),
  *   availableWhenMetered: (boolean|undefined),
+ *   dirty: (boolean|undefined),
  *   customIconUrl: (string|undefined),
  *   contentMimeType: (string|undefined),
  *   sharedWithMe: (boolean|undefined),
- *   shared: (boolean|undefined)
+ *   shared: (boolean|undefined),
+ *   starred: (boolean|undefined),
+ *   externalFileUrl: (string|undefined)
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-EntryProperties
  */
-var EntryProperties;
+chrome.fileManagerPrivate.EntryProperties;
 
 /**
  * @typedef {{
  *   totalSize: number,
  *   remainingSize: number
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-MountPointSizeStats
  */
-var MountPointSizeStats;
+chrome.fileManagerPrivate.MountPointSizeStats;
 
 /**
  * @typedef {{
@@ -52,20 +333,21 @@ var MountPointSizeStats;
  *   displayName: string,
  *   isCurrentProfile: boolean
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-ProfileInfo
  */
-var ProfileInfo;
+chrome.fileManagerPrivate.ProfileInfo;
 
 /**
  * @typedef {{
  *   volumeId: string,
  *   fileSystemId: (string|undefined),
  *   extensionId: (string|undefined),
- *   source: string,
+ *   source: !chrome.fileManagerPrivate.Source,
  *   volumeLabel: (string|undefined),
- *   profile: ProfileInfo,
+ *   profile: !chrome.fileManagerPrivate.ProfileInfo,
  *   sourcePath: (string|undefined),
- *   volumeType: string,
- *   deviceType: (string|undefined),
+ *   volumeType: !chrome.fileManagerPrivate.VolumeType,
+ *   deviceType: (!chrome.fileManagerPrivate.DeviceType|undefined),
  *   devicePath: (string|undefined),
  *   isParentDevice: (boolean|undefined),
  *   isReadOnly: boolean,
@@ -73,69 +355,76 @@ var ProfileInfo;
  *   hasMedia: boolean,
  *   configurable: boolean,
  *   watchable: boolean,
- *   mountCondition: (string|undefined),
- *   mountContext: (string|undefined)
+ *   mountCondition: (!chrome.fileManagerPrivate.MountCondition|undefined),
+ *   mountContext: (!chrome.fileManagerPrivate.MountContext|undefined)
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-VolumeMetadata
  */
-var VolumeMetadata;
+chrome.fileManagerPrivate.VolumeMetadata;
 
 /**
  * @typedef {{
- *   eventType: string,
- *   status: string,
- *   volumeMetadata: VolumeMetadata,
+ *   eventType: !chrome.fileManagerPrivate.MountCompletedEventType,
+ *   status: !chrome.fileManagerPrivate.MountCompletedStatus,
+ *   volumeMetadata: !chrome.fileManagerPrivate.VolumeMetadata,
  *   shouldNotify: boolean
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-MountCompletedEvent
  */
-var MountCompletedEvent;
+chrome.fileManagerPrivate.MountCompletedEvent;
 
 /**
  * @typedef {{
  *   fileUrl: string,
- *   transferState: string,
- *   transferType: string,
+ *   transferState: !chrome.fileManagerPrivate.TransferState,
+ *   transferType: !chrome.fileManagerPrivate.TransferType,
  *   processed: number,
  *   total: number,
  *   num_total_jobs: number
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-FileTransferStatus
  */
-var FileTransferStatus;
+chrome.fileManagerPrivate.FileTransferStatus;
 
 /**
  * @typedef {{
- *   type: string,
+ *   type: !chrome.fileManagerPrivate.DriveSyncErrorType,
  *   fileUrl: string
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DriveSyncErrorEvent
  */
-var DriveSyncErrorEvent;
+chrome.fileManagerPrivate.DriveSyncErrorEvent;
 
 /**
  * @typedef {{
- *   type: string,
+ *   type: !chrome.fileManagerPrivate.CopyProgressStatusType,
  *   sourceUrl: (string|undefined),
  *   destinationUrl: (string|undefined),
  *   size: (number|undefined),
  *   error: (string|undefined)
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-CopyProgressStatus
  */
-var CopyProgressStatus;
+chrome.fileManagerPrivate.CopyProgressStatus;
 
 /**
  * @typedef {{
  *   url: string,
- *   changes: Array
+ *   changes: !Array<!chrome.fileManagerPrivate.ChangeType>
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-FileChange
  */
-var FileChange;
+chrome.fileManagerPrivate.FileChange;
 
 /**
  * @typedef {{
- *   eventType: string,
+ *   eventType: !chrome.fileManagerPrivate.FileWatchEventType,
  *   entry: Object,
- *   changedFiles: (Array|undefined)
+ *   changedFiles: (!Array<!chrome.fileManagerPrivate.FileChange>|undefined)
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-FileWatchEvent
  */
-var FileWatchEvent;
+chrome.fileManagerPrivate.FileWatchEvent;
 
 /**
  * @typedef {{
@@ -147,57 +436,65 @@ var FileWatchEvent;
  *   allowRedeemOffers: boolean,
  *   timezone: string
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-Preferences
  */
-var Preferences;
+chrome.fileManagerPrivate.Preferences;
 
 /**
  * @typedef {{
  *   cellularDisabled: (boolean|undefined),
  *   hostedFilesDisabled: (boolean|undefined)
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-PreferencesChange
  */
-var PreferencesChange;
+chrome.fileManagerPrivate.PreferencesChange;
 
 /**
  * @typedef {{
  *   query: string,
  *   nextFeed: string
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-SearchParams
  */
-var SearchParams;
+chrome.fileManagerPrivate.SearchParams;
 
 /**
  * @typedef {{
  *   query: string,
- *   types: string,
+ *   types: !chrome.fileManagerPrivate.SearchType,
  *   maxResults: number
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-SearchMetadataParams
  */
-var SearchMetadataParams;
+chrome.fileManagerPrivate.SearchMetadataParams;
 
 /**
  * @typedef {{
  *   entry: Object,
  *   highlightedBaseName: string
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-SearchResult
  */
-var SearchResult;
+chrome.fileManagerPrivate.SearchResult;
 
 /**
  * @typedef {{
  *   type: string,
- *   reason: (string|undefined)
+ *   reason: (string|undefined),
+ *   hasCellularNetworkAccess: boolean
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DriveConnectionState
  */
-var DriveConnectionState;
+chrome.fileManagerPrivate.DriveConnectionState;
 
 /**
  * @typedef {{
- *   type: string,
+ *   type: !chrome.fileManagerPrivate.DeviceEventType,
  *   devicePath: string
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-DeviceEvent
  */
-var DeviceEvent;
+chrome.fileManagerPrivate.DeviceEvent;
 
 /**
  * @typedef {{
@@ -206,103 +503,109 @@ var DeviceEvent;
  *   configurable: boolean,
  *   watchable: boolean,
  *   multipleMounts: boolean,
- *   source: string
- * }}
- */
-var ProvidingExtension;
-
-/**
- * @typedef {{
- *   id: string,
- *   title: (string|undefined)
+ *   source: !chrome.fileManagerPrivate.manifestTypes.FileSystemProviderSource
  * }}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#type-ProvidingExtension
  */
-var EntryAction;
-
-/**
- * @const
- */
-chrome.fileManagerPrivate = {};
+chrome.fileManagerPrivate.ProvidingExtension;
 
 /**
  * Logout the current user for navigating to the re-authentication screen for
  * the Google account.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-logoutUserForReauthentication
  */
 chrome.fileManagerPrivate.logoutUserForReauthentication = function() {};
 
 /**
  * Cancels file selection.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-cancelDialog
  */
 chrome.fileManagerPrivate.cancelDialog = function() {};
 
 /**
  * Executes file browser task over selected files. |taskId| The unique
- * identifier of task to execute. |entries| Array of file entries |callback|
+ * identifier of task to execute. |entries| Array of entries |callback|
  * @param {string} taskId
- * @param {!Array<!Entry>} entries
- * @param {function((boolean|undefined))} callback |result| Result of the task
- *     execution.
+ * @param {!Array<Object>} entries
+ * @param {function(!chrome.fileManagerPrivate.TaskResult):void} callback
+ *     |result| Result of the task execution.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-executeTask
  */
 chrome.fileManagerPrivate.executeTask = function(taskId, entries, callback) {};
 
 /**
- * Sets the default task for the supplied MIME types and path extensions.
- * Lists of MIME types and entries may contain duplicates.
- * |taskId| The unique identifier of task to mark as default. |entries| Array
- * of selected file entries to extract path extensions from. |mimeTypes| Array
- * of selected file MIME types. |callback|
+ * Sets the default task for the supplied MIME types and path extensions. Lists
+ * of MIME types and URLs may contain duplicates. Additionally, the list of MIME
+ * types can be empty. |taskId| The unique identifier of task to mark as
+ * default. |entries| Array of selected entries to extract path extensions from.
+ * |mimeTypes| Array of selected file MIME types. |callback|
  * @param {string} taskId
- * @param {!Array<!Entry>} entries
+ * @param {!Array<Object>} entries
  * @param {!Array<string>} mimeTypes
- * @param {!function()} callback Callback that does not take arguments.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-setDefaultTask
  */
-chrome.fileManagerPrivate.setDefaultTask = function(taskId, entries, mimeTypes,
-    callback) {};
+chrome.fileManagerPrivate.setDefaultTask = function(taskId, entries, mimeTypes, callback) {};
 
 /**
  * Gets the list of tasks that can be performed over selected files. |entries|
  * Array of selected entries |callback|
- * @param {!Array<!Entry>} entries
- * @param {function((!Array<!FileTask>|undefined))} callback |tasks| The list of
- *     matched file entries for this task.
+ * @param {!Array<Object>} entries
+ * @param {function(!Array<!chrome.fileManagerPrivate.FileTask>):void} callback
+ *     |tasks| The list of matched file entries for this task.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getFileTasks
  */
 chrome.fileManagerPrivate.getFileTasks = function(entries, callback) {};
 
+/**
+ * Gets the MIME type of a file. |entry| Entry to be checked. |callback|
+ * @param {Object} entry
+ * @param {function(string):void} callback |result| Mime type of the file.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getMimeType
+ */
+chrome.fileManagerPrivate.getMimeType = function(entry, callback) {};
+
 /**
  * Gets localized strings and initialization data. |callback|
- * @param {function((!Object|undefined))} callback |result| Hash containing the
- *     string assets.
+ * @param {function(Object):void} callback |result| Hash containing the string
+ *     assets.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getStrings
  */
 chrome.fileManagerPrivate.getStrings = function(callback) {};
 
 /**
- * Adds file watch. |entry| Entry of file to watch |callback|
- * @param {!Entry} entry
- * @param {function((boolean|undefined))} callback |success| True when file
- *     watch is successfully added.
+ * Adds file watch. |entry| Entry to watch |callback|
+ * @param {Object} entry
+ * @param {function(boolean):void} callback |success| True when file watch is
+ *     successfully added.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-addFileWatch
  */
 chrome.fileManagerPrivate.addFileWatch = function(entry, callback) {};
 
 /**
- * Removes file watch. |entry| Entry of watched file to remove |callback|
- * @param {!Entry} entry
- * @param {function((boolean|undefined))} callback |success| True when file
- *     watch is successfully
- * removed.
+ * Removes file watch. |entry| Watched entry |callback|
+ * @param {Object} entry
+ * @param {function(boolean):void} callback |success| True when file watch is
+ *     successfully removed.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-removeFileWatch
  */
 chrome.fileManagerPrivate.removeFileWatch = function(entry, callback) {};
 
 /**
  * Enables the extenal file scheme necessary to initiate drags to the browser
  * window for files on the external backend.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-enableExternalFileScheme
  */
 chrome.fileManagerPrivate.enableExternalFileScheme = function() {};
 
 /**
- * Requests R/W access to the specified entries as |entryUrls|. Note, that only
- * files backed by external file system backend will be granted the access.
+ * Requests granting R/W permissions for the passed entries. It's a best effort
+ * operation. Some files may not be granted access if the url is invalid or not
+ * backed by the external file system. |entryUrls| Urls for the entries to be
+ * accessed. |callback|
  * @param {!Array<string>} entryUrls
- * @param {function()} callback Completion callback.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-grantAccess
  */
 chrome.fileManagerPrivate.grantAccess = function(entryUrls, callback) {};
 
@@ -312,10 +615,10 @@ chrome.fileManagerPrivate.grantAccess = function(entryUrls, callback) {};
  * |callback|
  * @param {!Array<string>} selectedPaths
  * @param {boolean} shouldReturnLocalPath
- * @param {function()} callback Callback that does not take arguments.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-selectFiles
  */
-chrome.fileManagerPrivate.selectFiles = function(selectedPaths,
-    shouldReturnLocalPath, callback) {};
+chrome.fileManagerPrivate.selectFiles = function(selectedPaths, shouldReturnLocalPath, callback) {};
 
 /**
  * Selects a file. |selectedPath| A selected path |index| Index of Filter
@@ -326,100 +629,112 @@ chrome.fileManagerPrivate.selectFiles = function(selectedPaths,
  * @param {number} index
  * @param {boolean} forOpening
  * @param {boolean} shouldReturnLocalPath
- * @param {function()} callback Callback that does not take arguments.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-selectFile
  */
-chrome.fileManagerPrivate.selectFile = function(selectedPath, index, forOpening,
-    shouldReturnLocalPath, callback) {};
+chrome.fileManagerPrivate.selectFile = function(selectedPath, index, forOpening, shouldReturnLocalPath, callback) {};
 
 /**
- * Requests additional properties for files. |entries| list of entries of files
- * |callback|
- * @param {!Array<!Entry>} entries
- * @param {!Array<string>} names
- * @param {function((!Array<!EntryProperties>|undefined))} callback
- *     |entryProperties| A dictionary containing properties of the requested
- *     entries.
+ * Requests additional properties for files. |entries| list of entries |names|
+ * list of requested properties by their names. |callback| Completion callback.
+ * May return less than requested properties     if some are not available. In
+ * the same time, it can return properties     which were not requested (if it's
+ * cheap to compute them).
+ * @param {!Array<Object>} entries
+ * @param {!Array<!chrome.fileManagerPrivate.EntryPropertyName>} names
+ * @param {function(!Array<!chrome.fileManagerPrivate.EntryProperties>):void}
+ *     callback |entryProperties| A dictionary containing properties of the
+ *     requested entries.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getEntryProperties
  */
-chrome.fileManagerPrivate.getEntryProperties = function(entries, names,
-    callback) {};
+chrome.fileManagerPrivate.getEntryProperties = function(entries, names, callback) {};
 
 /**
- * Pins/unpins a Drive file in the cache. |entry| Entry of a file to pin/unpin.
- * |pin| Pass true to pin the file. |callback| Completion callback.
+ * Pins/unpins a Drive file in the cache. |entry| Entry to pin/unpin. |pin| Pass
+ * true to pin the file. |callback| Completion callback.
  * $(ref:runtime.lastError) will be set if     there was an error.
- * @param {!Entry} entry
+ * @param {Object} entry
  * @param {boolean} pin
- * @param {function()} callback Callback that does not take arguments.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-pinDriveFile
  */
 chrome.fileManagerPrivate.pinDriveFile = function(entry, pin, callback) {};
 
 /**
- * Resolves file entries in the isolated file system and returns corresponding
+ * Resolves entries in the isolated file system and returns corresponding
  * entries in the external file system mounted to Chrome OS file manager
  * backend. If resolving entry fails, the entry will be just ignored and the
  * corresponding entry does not appear in the result.
- * @param {!Array<!Entry>} entries
- * @param {function((!Array<!Entry>|undefined))} callback Completion callback
- *     with resolved entries.
+ * @param {!Array<Object>} entries
+ * @param {function(!Array<Object>):void} callback |entries| External entries.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-resolveIsolatedEntries
  */
-chrome.fileManagerPrivate.resolveIsolatedEntries = function(entries,
-    callback) {};
+chrome.fileManagerPrivate.resolveIsolatedEntries = function(entries, callback) {};
 
 /**
- * Mount a resource or a file. |source| Mount point source. For compressed
- * files it is relative file path     within external file system |callback|
+ * Mount a resource or a file. |source| Mount point source. For compressed files
+ * it is relative file path     within external file system |callback|
  * @param {string} source
- * @param {function((string|undefined))} callback Callback with source path of
- *     the mount.
+ * @param {function(string):void} callback |sourcePath| Source path of the
+ *     mount.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-addMount
  */
 chrome.fileManagerPrivate.addMount = function(source, callback) {};
 
 /**
  * Unmounts a mounted resource. |volumeId| An ID of the volume.
  * @param {string} volumeId
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-removeMount
  */
 chrome.fileManagerPrivate.removeMount = function(volumeId) {};
 
 /**
  * Get the list of mounted volumes. |callback|
- * @param {function((!Array<!VolumeMetadata>|undefined))} callback Callback with
- *     the list of VolumeMetadata representing mounted volumes.
+ * @param {function(!Array<!chrome.fileManagerPrivate.VolumeMetadata>):void}
+ *     callback |volumeMetadataList| The list of VolumeMetadata representing
+ *     mounted volumes.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getVolumeMetadataList
  */
 chrome.fileManagerPrivate.getVolumeMetadataList = function(callback) {};
 
 /**
  * Cancels ongoing file transfers for selected files. |entries| Array of files
- * for which ongoing transfer should be canceled.
- * @param {!Array<!FileEntry>} entries
- * @param {function()} callback
+ * for which ongoing transfer should be canceled. |callback| Completion callback
+ * of the cancel.
+ * @param {!Array<Object>} entries
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-cancelFileTransfers
  */
 chrome.fileManagerPrivate.cancelFileTransfers = function(entries, callback) {};
 
 /**
- * Cancels all ongoing file transfers.
- * @param {function()} callback
+ * Cancels all ongoing file transfers. |callback| Completion callback of the
+ * cancel.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-cancelAllFileTransfers
  */
 chrome.fileManagerPrivate.cancelAllFileTransfers = function(callback) {};
 
 /**
  * Starts to copy an entry. If the source is a directory, the copy is done
- * recursively. |entry| Entry of the source entry to be copied. |parent| Entry
- * of the destination directory. |newName| Name of the new entry. It must not
- * contain '/'. |callback| Completion callback.
- * @param {!Entry} entry
- * @param {!DirectoryEntry} parentEntry
+ * recursively. |entry| Entry of the source entry to be copied. |parentEntry|
+ * Entry for the destination (parent) directory. |newName| Name of the new
+ * entry. It must not contain '/'. |callback| Completion callback.
+ * @param {Object} entry
+ * @param {Object} parentEntry
  * @param {string} newName
- * @param {function((number|undefined))} callback |copyId| ID of the copy task.
- *     Can be used to identify the progress, and to cancel the task.
+ * @param {function(number):void} callback |copyId| ID of the copy task. Can be
+ *     used to identify the progress, and to cancel the task.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-startCopy
  */
-chrome.fileManagerPrivate.startCopy = function(entry, parentEntry, newName,
-    callback) {};
+chrome.fileManagerPrivate.startCopy = function(entry, parentEntry, newName, callback) {};
 
 /**
  * Cancels the running copy task. |copyId| ID of the copy task to be cancelled.
  * |callback| Completion callback of the cancel.
  * @param {number} copyId
- * @param {function()} callback Callback that does not take arguments.
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-cancelCopy
  */
 chrome.fileManagerPrivate.cancelCopy = function(copyId, callback) {};
 
@@ -427,91 +742,105 @@ chrome.fileManagerPrivate.cancelCopy = function(copyId, callback) {};
  * Retrieves total and remaining size of a mount point. |volumeId| ID of the
  * volume to be checked. |callback|
  * @param {string} volumeId
- * @param {function((!MountPointSizeStats|undefined))} callback Name/value pairs
- *     of size stats. Will be undefined if stats could not be determined.
+ * @param {function(!chrome.fileManagerPrivate.MountPointSizeStats):void}
+ *     callback |sizeStats| Name/value pairs of size stats. Will be undefined if
+ *     stats could not be determined.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getSizeStats
  */
 chrome.fileManagerPrivate.getSizeStats = function(volumeId, callback) {};
 
 /**
  * Formats a mounted volume. |volumeId| ID of the volume to be formatted.
  * @param {string} volumeId
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-formatVolume
  */
 chrome.fileManagerPrivate.formatVolume = function(volumeId) {};
 
 /**
  * Retrieves file manager preferences. |callback|
- * @param {function((!Preferences|undefined))} callback
+ * @param {function(!chrome.fileManagerPrivate.Preferences):void} callback
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getPreferences
  */
 chrome.fileManagerPrivate.getPreferences = function(callback) {};
 
 /**
  * Sets file manager preferences. |changeInfo|
- * @param {PreferencesChange} changeInfo
+ * @param {!chrome.fileManagerPrivate.PreferencesChange} changeInfo
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-setPreferences
  */
 chrome.fileManagerPrivate.setPreferences = function(changeInfo) {};
 
 /**
  * Performs drive content search. |searchParams| |callback|
- * @param {SearchParams} searchParams
- * @param {function((!Array<Entry>|undefined), (string|undefined))} callback
- * Entries and ID of the feed that contains next chunk of the search result.
- * Should be sent to the next searchDrive request to perform incremental search.
+ * @param {!chrome.fileManagerPrivate.SearchParams} searchParams
+ * @param {function(!Array<Object>, string):void} callback |entries| |nextFeed|
+ *     ID of the feed that contains next chunk of the search result.     Should
+ *     be sent to the next searchDrive request to perform     incremental
+ *     search.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-searchDrive
  */
 chrome.fileManagerPrivate.searchDrive = function(searchParams, callback) {};
 
 /**
  * Performs drive metadata search. |searchParams| |callback|
- * @param {SearchMetadataParams} searchParams
- * @param {function((!Array<!SearchResult>|undefined))} callback
+ * @param {!chrome.fileManagerPrivate.SearchMetadataParams} searchParams
+ * @param {function(!Array<!chrome.fileManagerPrivate.SearchResult>):void}
+ *     callback
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-searchDriveMetadata
  */
-chrome.fileManagerPrivate.searchDriveMetadata = function(searchParams,
-    callback) {};
+chrome.fileManagerPrivate.searchDriveMetadata = function(searchParams, callback) {};
 
 /**
- * Search for files in the given volume, whose content hash matches the list of
- * given hashes.
+ * Search files in the volume having |volumeId| by using |hashList|.
+ * sub-directories) the given |targetDirectoryUrl|.
  * @param {string} volumeId
- * @param {!Array<string>} hashes
- * @param {function((!Object<string, !Array<string>>|undefined))} callback
+ * @param {!Array<string>} hashList
+ * @param {function(Object):void} callback |urls| The map of hash and array of
+ *     FileEntry's URL. The array can be empty if the corresponding file is not
+ *     found.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-searchFilesByHashes
  */
-chrome.fileManagerPrivate.searchFilesByHashes = function(volumeId, hashes,
-    callback) {};
+chrome.fileManagerPrivate.searchFilesByHashes = function(volumeId, hashList, callback) {};
 
 /**
  * Create a zip file for the selected files. |parentEntry| Entry of the
- * directory containing the selected files. |entries| Selected entries.
- * The files must be under the directory specified by |parentEntry|. |destName|
- * Name of the destination zip file. The zip file will be created under the
- * directory specified by |parentEntry|.
- * @param {!DirectoryEntry} parentEntry
- * @param {!Array<!Entry>} entries
+ * directory containing the selected files. |entries| Entries of the selected
+ * files. The files must be under the     directory specified by |parentEntry|.
+ * |destName| Name of the destination zip file. The zip file will be created
+ * under the directory specified by |parentEntry|. |callback| TODO(mtomasz):
+ * Swap order of |entries| and |parentEntry|.
+ * @param {Object} parentEntry
+ * @param {!Array<Object>} entries
  * @param {string} destName
- * @param {function((boolean|undefined))} callback
+ * @param {function(boolean):void} callback
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-zipSelection
  */
-chrome.fileManagerPrivate.zipSelection = function(parentEntry, entries,
-    destName, callback) {};
+chrome.fileManagerPrivate.zipSelection = function(parentEntry, entries, destName, callback) {};
 
 /**
  * Retrieves the state of the current drive connection. |callback|
- * @param {function((!DriveConnectionState|undefined))} callback
+ * @param {function(!chrome.fileManagerPrivate.DriveConnectionState):void}
+ *     callback
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getDriveConnectionState
  */
 chrome.fileManagerPrivate.getDriveConnectionState = function(callback) {};
 
 /**
  * Checks whether the path name length fits in the limit of the filesystem.
- * |parentEntry| The parent directory entry. |name| The name of the file.
- * |callback| Called back when the check is finished.
- * @param {!DirectoryEntry} parentEntry
+ * |parentEntry| The entry of the parent directory entry. |name| The name of the
+ * file. |callback| Called back when the check is finished.
+ * @param {Object} parentEntry
  * @param {string} name
- * @param {function((boolean|undefined))} callback |result| true if the length
- *     is in the valid range, false otherwise.
+ * @param {function(boolean):void} callback |result| true if the length is in
+ *     the valid range, false otherwise.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-validatePathNameLength
  */
-chrome.fileManagerPrivate.validatePathNameLength = function(
-    parentEntry, name, callback) {};
+chrome.fileManagerPrivate.validatePathNameLength = function(parentEntry, name, callback) {};
 
 /**
  * Changes the zoom factor of the Files.app. |operation| Zooming mode.
- * @param {string} operation
+ * @param {!chrome.fileManagerPrivate.ZoomOperationType} operation
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-zoom
  */
 chrome.fileManagerPrivate.zoom = function(operation) {};
 
@@ -519,186 +848,207 @@ chrome.fileManagerPrivate.zoom = function(operation) {};
  * Requests a Drive API OAuth2 access token. |refresh| Whether the token should
  * be refetched instead of using the cached     one. |callback|
  * @param {boolean} refresh
- * @param {function((string|undefined))} callback |accessToken| OAuth2 access
- *     token, or an empty string if failed to fetch.
+ * @param {function(string):void} callback |accessToken| OAuth2 access token, or
+ *     an empty string if failed to fetch.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-requestAccessToken
  */
 chrome.fileManagerPrivate.requestAccessToken = function(refresh, callback) {};
 
 /**
  * Requests a Webstore API OAuth2 access token. |callback|
- * @param {function((string|undefined))} callback |accessToken| OAuth2 access
- *     token, or an empty string if failed to fetch.
+ * @param {function(string):void} callback |accessToken| OAuth2 access token, or
+ *     an empty string if failed to fetch.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-requestWebStoreAccessToken
  */
 chrome.fileManagerPrivate.requestWebStoreAccessToken = function(callback) {};
 
 /**
- * Requests a share dialog url for the specified file.
- * @param {!Entry} entry
- * @param {function((string|undefined))} callback Callback with the result url.
+ * Requests a share dialog url for the specified file. |entry| The entry to
+ * share. |callback|
+ * @param {Object} entry
+ * @param {function(string):void} callback |url| Result url.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getShareUrl
  */
 chrome.fileManagerPrivate.getShareUrl = function(entry, callback) {};
 
 /**
- * Requests a download url to download the file contents.
- * @param {!Entry} entry
- * @param {function((string|undefined))} callback Callback with the result url.
+ * Requests a download url to download the file contents. |entry| The entry to
+ * download. |callback|
+ * @param {Object} entry
+ * @param {function(string):void} callback |url| Result url.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getDownloadUrl
  */
 chrome.fileManagerPrivate.getDownloadUrl = function(entry, callback) {};
 
 /**
- * Requests to share drive files.
- * @param {!Entry} entry
- * @param {string} shareType
- * @param {function()} callback Callback that does not take arguments.
+ * Requests to share drive files. |entry| Entry to be shared. |shareType| Type
+ * of access that is getting granted.
+ * @param {Object} entry
+ * @param {!chrome.fileManagerPrivate.DriveShareType} shareType
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-requestDriveShare
  */
-chrome.fileManagerPrivate.requestDriveShare = function(entry, shareType,
-    callback) {};
-
-/**
- * Requests to install a webstore item. |item_id| The id of the item to
- * install. |silentInstallation| False to show installation prompt. True not to
- * show. |callback|
- * @param {string} itemId
- * @param {boolean} silentInstallation
- * @param {function()} callback Callback that does not take arguments.
- */
-chrome.fileManagerPrivate.installWebstoreItem = function(itemId,
-    silentInstallation, callback) {};
+chrome.fileManagerPrivate.requestDriveShare = function(entry, shareType, callback) {};
 
 /**
  * Obtains a list of profiles that are logged-in.
- * @param {function((!Array<!ProfileInfo>|undefined), (string|undefined),
- *     (string|undefined))} callback Callback with list of profile information,
- *     |runningProfile| ID of the profile that runs the application instance.
- *     |showingProfile| ID of the profile that shows the application window.
+ * @param {function(!Array<!chrome.fileManagerPrivate.ProfileInfo>, string, string):void}
+ *     callback |profiles| List of profile information. |runningProfile| ID of
+ *     the profile that runs the application instance. |showingProfile| ID of
+ *     the profile that shows the application window.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getProfiles
  */
 chrome.fileManagerPrivate.getProfiles = function(callback) {};
 
 /**
  * Opens inspector window. |type| InspectionType which specifies how to open
  * inspector.
- * @param {string} type
+ * @param {!chrome.fileManagerPrivate.InspectionType} type
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-openInspector
  */
 chrome.fileManagerPrivate.openInspector = function(type) {};
 
 /**
- * Computes an MD5 checksum for the given file.
- * @param {!Entry} entry
- * @param {function((string|undefined))} callback
+ * Computes an MD5 checksum for the given file. |entry| The entry of the file to
+ * checksum. |callback|
+ * @param {Object} entry
+ * @param {function(string):void} callback |checksum| Result checksum.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-computeChecksum
  */
 chrome.fileManagerPrivate.computeChecksum = function(entry, callback) {};
 
 /**
- * Gets the MIME type of a file.
- * @param {!Entry} entry
- * @param {function((string|undefined))} callback Callback that MIME type of the
- *     file is passed.
- */
-chrome.fileManagerPrivate.getMimeType = function(entry, callback) {};
-
-/**
- * Gets a flag indicating whether user metrics reporting is enabled.
- * @param {function((boolean|undefined))} callback
+ * Is UMA enabled?
+ * @param {function(boolean):void} callback |result| Boolean result returned by
+ *     the invoked function.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-isUMAEnabled
  */
 chrome.fileManagerPrivate.isUMAEnabled = function(callback) {};
 
 /**
  * Sets a tag on a file or a directory. Only Drive files are supported.
- * @param {!Entry} entry
- * @param {string} visibility 'private' or 'public'
+ * @param {Object} entry
+ * @param {!chrome.fileManagerPrivate.EntryTagVisibility} visibility
  * @param {string} key
  * @param {string} value
- * @param {function()} callback
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-setEntryTag
  */
-chrome.fileManagerPrivate.setEntryTag = function(entry, visibility, key,
-    value, callback) {};
+chrome.fileManagerPrivate.setEntryTag = function(entry, visibility, key, value, callback) {};
 
 /**
- * Gets a flag indicating whether PiexLoader is enabled.
- * @param {function((boolean|undefined))} callback
+ * Returns if Piex loader is enabled.
+ * @param {function(boolean):void} callback |result| Boolean result returned by
+ *     the invoked function.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-isPiexLoaderEnabled
  */
 chrome.fileManagerPrivate.isPiexLoaderEnabled = function(callback) {};
 
 /**
  * Returns list of available providing extensions.
- * @param {function((!Array<!ProvidingExtension>|undefined))} callback
+ * @param {function(!Array<!chrome.fileManagerPrivate.ProvidingExtension>):void}
+ *     callback |extensions| List of providing extensions.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getProvidingExtensions
  */
 chrome.fileManagerPrivate.getProvidingExtensions = function(callback) {};
 
 /**
  * Requests adding a new provided file system. If not possible, then an error
  * via chrome.runtime.lastError is returned.
- * @param {string} extensionId
- * @param {function()} callback
+ * @param {string} extension_id
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-addProvidedFileSystem
  */
-chrome.fileManagerPrivate.addProvidedFileSystem =
-    function(extensionId, callback) {};
+chrome.fileManagerPrivate.addProvidedFileSystem = function(extension_id, callback) {};
 
 /**
- * Requests configuring an existing file system. If not possible, then returns
- * an error via chrome.runtime.lastError.
+ * Requests configuring an existing volume. If not possible, then returns an
+ * error via chrome.runtime.lastError.
  * @param {string} volumeId
- * @param {function()} callback
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-configureVolume
  */
 chrome.fileManagerPrivate.configureVolume = function(volumeId, callback) {};
 
 /**
- * Requests fetching list of actions for the specified set of entries. If not
- * possible, then returns an error via chrome.runtime.lastError.
- * @param {!Array<!Entry>} entries
- * @param {function((!Array<!EntryAction>|undefined))} callback
+ * Requests list of custom actions for the specified entries. If not possible,
+ * then an error via chrome.runtime.lastError is returned.
+ * @param {!Array<Object>} entries
+ * @param {function(!Array<!chrome.fileManagerPrivate.fileSystemProvider.Action>):void}
+ *     callback |actions| List of actions.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getCustomActions
  */
 chrome.fileManagerPrivate.getCustomActions = function(entries, callback) {};
 
+/**
+ * Executes a custom action for a set of entries. If not possible, then an error
+ * via chrome.runtime.lastError is returned.
+ * @param {!Array<Object>} entries
+ * @param {string} actionId
+ * @param {function():void} callback Callback that does not take arguments.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-executeCustomAction
+ */
+chrome.fileManagerPrivate.executeCustomAction = function(entries, actionId, callback) {};
+
 /**
  * Get the total size of a directory. |entry| Entry of the target directory.
  * |callback|
- * @param {!DirectoryEntry} entry
- * @param {function(number)} callback
+ * @param {Object} entry
+ * @param {function(number):void} callback |size| result size.
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#method-getDirectorySize
  */
 chrome.fileManagerPrivate.getDirectorySize = function(entry, callback) {};
 
 /**
- * Executes the action on the specified set of entries. If not possible, then
- * returns an error via chrome.runtime.lastError.
- * @param {!Array<!Entry>} entries
- * @param {string} actionId
- * @param {function()} callback
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onMountCompleted
  */
-chrome.fileManagerPrivate.executeCustomAction = function(
-    entries, actionId, callback) {};
-
-/** @type {!ChromeEvent} */
 chrome.fileManagerPrivate.onMountCompleted;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onFileTransfersUpdated
+ */
 chrome.fileManagerPrivate.onFileTransfersUpdated;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onCopyProgress
+ */
 chrome.fileManagerPrivate.onCopyProgress;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onDirectoryChanged
+ */
 chrome.fileManagerPrivate.onDirectoryChanged;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onPreferencesChanged
+ */
 chrome.fileManagerPrivate.onPreferencesChanged;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onDriveConnectionStatusChanged
+ */
 chrome.fileManagerPrivate.onDriveConnectionStatusChanged;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onDeviceChanged
+ */
 chrome.fileManagerPrivate.onDeviceChanged;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onDriveSyncError
+ */
 chrome.fileManagerPrivate.onDriveSyncError;
 
-/** @type {!ChromeEvent} */
+/**
+ * @type {!ChromeEvent}
+ * @see https://developer.chrome.com/extensions/fileManagerPrivate#event-onAppsUpdated
+ */
 chrome.fileManagerPrivate.onAppsUpdated;
-
-/** @enum {string} */
-chrome.fileManagerPrivate.Verb = {
-  OPEN_WITH: 'open_with',
-  ADD_TO: 'add_to',
-  PACK_WITH: 'pack_with',
-  SHARE_WITH: 'share_with',
-};