arc: Revamp the ArcBridgeService interface

chrome/browser/chromeos/arc/arc_downloads_watcher_service.h

Index: chrome/browser/chromeos/arc/arc_downloads_watcher_service.h
diff --git a/chrome/browser/chromeos/arc/arc_downloads_watcher_service.h b/chrome/browser/chromeos/arc/arc_downloads_watcher_service.h
index 415230f6902ebab131ca67580212e141ec12b1de..51b4b38a2516e1d4a5ece5970e5cf5c151c4b770 100644
--- a/chrome/browser/chromeos/arc/arc_downloads_watcher_service.h
+++ b/chrome/browser/chromeos/arc/arc_downloads_watcher_service.h
@@ -23,15 +23,16 @@ namespace arc {
 
 // Watches Downloads directory and registers newly created media files to
 // Android MediaProvider.
-class ArcDownloadsWatcherService : public ArcService,
-                                   public ArcBridgeService::Observer {
+class ArcDownloadsWatcherService
+    : public ArcService,
+      public ArcBridgeService::InstanceObserver<mojom::FileSystemInstance> {
  public:
   explicit ArcDownloadsWatcherService(ArcBridgeService* bridge_service);
   ~ArcDownloadsWatcherService() override;
 
-  // ArcBridgeService::Observer
-  void OnFileSystemInstanceReady() override;
-  void OnFileSystemInstanceClosed() override;
+  // ArcBridgeService::InstanceObserver<mojom::FileSystemInstance>
+  void OnInstanceReady(mojom::FileSystemInstance*, uint32_t version) override;
+  void OnInstanceClosed(mojom::FileSystemInstance*) override;
 
  private:
   class DownloadsWatcher;