Filter DriveFS file change notifications to just watched directories.

Currently, all DriveFS change notifications are forwarded to the UI.
Some parts do their own checks for matching the expected directory, but
others do not; one part that does not is DirectoryTree, which triggers a
rescan of any changed directories. Filter to just directories with a
registered watcher like the old Drive client does.

Bug: 943886
Change-Id: If106ef054e5bfbdd16697e41d74b176996c6750f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1529896Reviewed-by: Sergei Datsenko <dats@chromium.org>
Commit-Queue: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642357}

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

@@ -160,7 +160,8 @@ void DriveFsEventRouter::OnFilesChanged(
                     CHANGE_TYPE_ADD_OR_UPDATE);
     }
     for (auto& event : events) {
-      DispatchOnDirectoryChangedEventToExtension(extension_id, event.second);
+      DispatchOnDirectoryChangedEventToExtension(extension_id, event.first,
+                                                 event.second);
     }
   }
 }
@@ -204,7 +205,11 @@ void DriveFsEventRouter::DispatchOnFileTransfersUpdatedEventToExtension(
 
 void DriveFsEventRouter::DispatchOnDirectoryChangedEventToExtension(
     const std::string& extension_id,
+    const base::FilePath& directory,
     const extensions::api::file_manager_private::FileWatchEvent& event) {
+  if (!IsPathWatched(directory)) {
+    return;
+  }
   DispatchEventToExtension(
       extension_id,
       extensions::events::FILE_MANAGER_PRIVATE_ON_DIRECTORY_CHANGED,

chrome/browser/chromeos/extensions/file_manager/drivefs_event_router.h

@@ -59,12 +59,15 @@ class DriveFsEventRouter : public drivefs::DriveFsHostObserver {
 
   virtual std::string GetDriveFileSystemName() = 0;
 
+  virtual bool IsPathWatched(const base::FilePath& path) = 0;
+
   void DispatchOnFileTransfersUpdatedEventToExtension(
       const std::string& extension_id,
       const extensions::api::file_manager_private::FileTransferStatus& status);
 
   void DispatchOnDirectoryChangedEventToExtension(
       const std::string& extension_id,
+      const base::FilePath& directory,
       const extensions::api::file_manager_private::FileWatchEvent& event);
 
   // Helper method for dispatching an event to an extension.

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

@@ -68,7 +68,9 @@ testing::Matcher<const base::ListValue&> MatchFileWatchEvent(
 
 class TestDriveFsEventRouter : public DriveFsEventRouter {
  public:
-  TestDriveFsEventRouter() = default;
+  TestDriveFsEventRouter() {
+    ON_CALL(*this, IsPathWatched).WillByDefault(testing::Return(true));
+  }
 
   void DispatchEventToExtension(
       const std::string& extension_id,
@@ -82,6 +84,7 @@ class TestDriveFsEventRouter : public DriveFsEventRouter {
                void(const std::string& extension_id,
                     const std::string& name,
                     const base::ListValue& event));
+  MOCK_METHOD1(IsPathWatched, bool(const base::FilePath&));
 
   GURL ConvertDrivePathToFileSystemUrl(
       const base::FilePath& file_path,
@@ -529,6 +532,10 @@ TEST_F(DriveFsEventRouterTest, OnFilesChanged_Basic) {
         file_manager_private::CHANGE_TYPE_ADD_OR_UPDATE);
   }
 
+  EXPECT_CALL(mock(), IsPathWatched(base::FilePath("/root")))
+      .WillOnce(testing::Return(true));
+  EXPECT_CALL(mock(), IsPathWatched(base::FilePath("/other")))
+      .WillOnce(testing::Return(false));
   EXPECT_CALL(mock(),
               DispatchEventToExtensionImpl(
                   "ext", file_manager_private::OnDirectoryChanged::kEventName,
@@ -541,6 +548,8 @@ TEST_F(DriveFsEventRouterTest, OnFilesChanged_Basic) {
                        drivefs::mojom::FileChange::Type::kCreate);
   changes.emplace_back(base::FilePath("/root/c"),
                        drivefs::mojom::FileChange::Type::kModify);
+  changes.emplace_back(base::FilePath("/other/a"),
+                       drivefs::mojom::FileChange::Type::kModify);
   observer().OnFilesChanged(changes);
 }
 

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

@@ -391,7 +391,11 @@ class JobEventRouterImpl : public JobEventRouter {
 
 class DriveFsEventRouterImpl : public DriveFsEventRouter {
  public:
-  explicit DriveFsEventRouterImpl(Profile* profile) : profile_(profile) {}
+  DriveFsEventRouterImpl(
+      Profile* profile,
+      const std::map<base::FilePath, std::unique_ptr<FileWatcher>>*
+          file_watchers)
+      : profile_(profile), file_watchers_(file_watchers) {}
 
  private:
   std::set<std::string> GetEventListenerExtensionIds(
@@ -420,6 +424,14 @@ class DriveFsEventRouterImpl : public DriveFsEventRouter {
         .value();
   }
 
+  bool IsPathWatched(const base::FilePath& path) override {
+    base::FilePath absolute_path =
+        DriveIntegrationServiceFactory::FindForProfile(profile_)
+            ->GetMountPointPath();
+    return base::FilePath("/").AppendRelativePath(path, &absolute_path) &&
+           base::ContainsKey(*file_watchers_, absolute_path);
+  }
+
   void DispatchEventToExtension(
       const std::string& extension_id,
       extensions::events::HistogramValue histogram_value,
@@ -431,6 +443,8 @@ class DriveFsEventRouterImpl : public DriveFsEventRouter {
   }
 
   Profile* const profile_;
+  const std::map<base::FilePath, std::unique_ptr<FileWatcher>>* const
+      file_watchers_;
 
   DISALLOW_COPY_AND_ASSIGN(DriveFsEventRouterImpl);
 };
@@ -442,7 +456,8 @@ EventRouter::EventRouter(Profile* profile)
       profile_(profile),
       device_event_router_(std::make_unique<DeviceEventRouterImpl>(profile)),
       job_event_router_(std::make_unique<JobEventRouterImpl>(profile)),
-      drivefs_event_router_(std::make_unique<DriveFsEventRouterImpl>(profile)),
+      drivefs_event_router_(
+          std::make_unique<DriveFsEventRouterImpl>(profile, &file_watchers_)),
       dispatch_directory_change_event_impl_(
           base::Bind(&EventRouter::DispatchDirectoryChangeEventImpl,
                      base::Unretained(this))),