mediaview: Mount ARC documents provider file system volumes.

components/arc/arc_service_manager.h

Index: components/arc/arc_service_manager.h
diff --git a/components/arc/arc_service_manager.h b/components/arc/arc_service_manager.h
index 81a4ea9e98b2e715e289b112d3cae2660d72cbd6..04be5dd7a8b4f3540fdcda409b1a77d827cebe9c 100644
--- a/components/arc/arc_service_manager.h
+++ b/components/arc/arc_service_manager.h
@@ -19,6 +19,7 @@
 namespace arc {
 
 class ArcBridgeService;
+class ArcFileSystemObserver;
 class ArcIntentHelperObserver;
 class ArcService;
 
@@ -31,10 +32,13 @@ class ArcServiceManager {
     // Called when ArcServiceManager is being shut down. Observer
     // implementation should clean up ARC related stuff here. One of the
     // typical use cases is calling ArcServiceManager::RemoveObserver().
-    virtual void OnArcShutdown() = 0;
+    virtual void OnArcShutdown() {}
 
     // Called when intent filters are added or removed.
-    virtual void OnIntentFiltersUpdated() = 0;
+    virtual void OnIntentFiltersUpdated() {}
+
+    // Called when ARC filesystems are ready.
+    virtual void OnFileSystemsReady() {}
 
    protected:
     virtual ~Observer() = default;
@@ -73,12 +77,18 @@ class ArcServiceManager {
     return activity_resolver_;
   }
 
-  // Returns the IntentHelperObserver instance owned by ArcServiceManager.
+  // Returns the ArcIntentHelperObserver instance owned by ArcServiceManager.
   ArcIntentHelperObserver* intent_helper_observer() {
     return intent_helper_observer_.get();
   }
 
+  // Returns the ArcFileSystemObserver instance owned by ArcServiceManager.
+  ArcFileSystemObserver* file_system_observer() {
+    return file_system_observer_.get();
+  }
+
  private:
+  class FileSystemObserverImpl;    // implemented in arc_service_manager.cc.
   class IntentHelperObserverImpl;  // implemented in arc_service_manager.cc.
 
   base::ThreadChecker thread_checker_;
@@ -87,6 +97,9 @@ class ArcServiceManager {
   // An object for observing the ArcIntentHelper instance in |services_|.
   std::unique_ptr<ArcIntentHelperObserver> intent_helper_observer_;
 
+  // An object for observing the ArcFileSystemService instance in |services_|.
+  std::unique_ptr<ArcFileSystemObserver> file_system_observer_;
+
   std::unique_ptr<ArcBridgeService> arc_bridge_service_;
   std::vector<std::unique_ptr<ArcService>> services_;
   scoped_refptr<ActivityIconLoader> icon_loader_;