fix crash for native providers

This change fixes a crash when Native Filesystem Providers call the
Service::RequestMount() function via the providers_menu in the CrOS
Files App.

Bug: chromium:827023
Test: manually verified on eve
Change-Id: I25ba6fb33fe9c9ae1a360368c0d8bb45728fc7a1
Reviewed-on: https://chromium-review.googlesource.com/972421Reviewed-by: Naoki Fukino <fukino@chromium.org>
Reviewed-by: Tomasz Mikolajewski <mtomasz@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546741}

chrome/browser/chromeos/file_system_provider/extension_provider.cc

@@ -13,6 +13,7 @@
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system.h"
 #include "chrome/browser/chromeos/file_system_provider/throttled_file_system.h"
 #include "chrome/browser/profiles/profile.h"
+#include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/permissions/permissions_data.h"
 
@@ -88,6 +89,27 @@ const IconSet& ExtensionProvider::GetIconSet() const {
   return icon_set_;
 }
 
+bool ExtensionProvider::RequestMount(Profile* profile) {
+  extensions::EventRouter* const event_router =
+      extensions::EventRouter::Get(profile);
+  DCHECK(event_router);
+
+  if (!event_router->ExtensionHasEventListener(
+          provider_id_.GetExtensionId(), extensions::api::file_system_provider::
+                                             OnMountRequested::kEventName)) {
+    return false;
+  }
+
+  event_router->DispatchEventToExtension(
+      provider_id_.GetExtensionId(),
+      std::make_unique<extensions::Event>(
+          extensions::events::FILE_SYSTEM_PROVIDER_ON_MOUNT_REQUESTED,
+          extensions::api::file_system_provider::OnMountRequested::kEventName,
+          std::unique_ptr<base::ListValue>(new base::ListValue())));
+
+  return true;
+}
+
 ExtensionProvider::ExtensionProvider(
     const extensions::ExtensionId& extension_id,
     const ProvidingExtensionInfo& info)

chrome/browser/chromeos/file_system_provider/extension_provider.h

@@ -51,6 +51,7 @@ class ExtensionProvider : public ProviderInterface {
   const ProviderId& GetId() const override;
   const std::string& GetName() const override;
   const IconSet& GetIconSet() const override;
+  bool RequestMount(Profile* profile) override;
 
  private:
   ExtensionProvider(const extensions::ExtensionId& extension_id,

chrome/browser/chromeos/file_system_provider/fake_extension_provider.cc

@@ -53,6 +53,10 @@ const IconSet& FakeExtensionProvider::GetIconSet() const {
   return icon_set_;
 }
 
+bool FakeExtensionProvider::RequestMount(Profile* profile) {
+  return true;
+}
+
 FakeExtensionProvider::FakeExtensionProvider(
     const extensions::ExtensionId& extension_id,
     const Capabilities& capabilities)

chrome/browser/chromeos/file_system_provider/fake_extension_provider.h

@@ -36,6 +36,7 @@ class FakeExtensionProvider : public ProviderInterface {
   const ProviderId& GetId() const override;
   const std::string& GetName() const override;
   const IconSet& GetIconSet() const override;
+  bool RequestMount(Profile* profile) override;
 
  protected:
   FakeExtensionProvider(const extensions::ExtensionId& extension_id,

chrome/browser/chromeos/file_system_provider/provider_interface.h

@@ -67,6 +67,10 @@ class ProviderInterface {
 
   // Returns an icon URL set for the provider.
   virtual const IconSet& GetIconSet() const = 0;
+
+  // Requests mounting a new file system. Returns false if the request could not
+  // be created, true otherwise.
+  virtual bool RequestMount(Profile* profile) = 0;
 };
 
 }  // namespace file_system_provider

chrome/browser/chromeos/file_system_provider/service.cc

@@ -20,7 +20,6 @@
 #include "chrome/browser/chromeos/file_system_provider/throttled_file_system.h"
 #include "components/prefs/pref_service.h"
 #include "components/prefs/scoped_user_pref_update.h"
-#include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/common/extension_id.h"
@@ -262,24 +261,8 @@ bool Service::RequestUnmount(const ProviderId& provider_id,
 bool Service::RequestMount(const ProviderId& provider_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  extensions::EventRouter* const event_router =
-      extensions::EventRouter::Get(profile_);
-  DCHECK(event_router);
-
-  if (!event_router->ExtensionHasEventListener(
-          provider_id.GetExtensionId(), extensions::api::file_system_provider::
-                                            OnMountRequested::kEventName)) {
-    return false;
-  }
-
-  event_router->DispatchEventToExtension(
-      provider_id.GetExtensionId(),
-      std::make_unique<extensions::Event>(
-          extensions::events::FILE_SYSTEM_PROVIDER_ON_MOUNT_REQUESTED,
-          extensions::api::file_system_provider::OnMountRequested::kEventName,
-          std::unique_ptr<base::ListValue>(new base::ListValue())));
-
-  return true;
+  ProviderInterface* const provider = GetProvider(provider_id);
+  return provider->RequestMount(profile_);
 }
 
 std::vector<ProvidedFileSystemInfo> Service::GetProvidedFileSystemInfoList() {

chrome/browser/chromeos/smb_client/smb_provider.cc

@@ -57,5 +57,9 @@ const IconSet& SmbProvider::GetIconSet() const {
   return icon_set_;
 }
 
+bool SmbProvider::RequestMount(Profile* profile) {
+  return false;
+}
+
 }  // namespace smb_client
 }  // namespace chromeos

chrome/browser/chromeos/smb_client/smb_provider.h

@@ -43,6 +43,7 @@ class SmbProvider : public ProviderInterface {
   const ProviderId& GetId() const override;
   const std::string& GetName() const override;
   const IconSet& GetIconSet() const override;
+  bool RequestMount(Profile* profile) override;
 
  private:
   ProviderId provider_id_;