Implement mediaGalleriesPrivate api to notify extensions about gallery changed events.

chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h

Index: chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h
diff --git a/chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h b/chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h
index 39f014b92e6f2b743954410ef45cf113b693fe7e..2f5b11c31ea87670ee694a017fbeee7abf50bbcd 100644
--- a/chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h
+++ b/chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h
@@ -4,21 +4,28 @@
 
 // Manages events for the private Chrome extensions media galleries API. This
 // is temporary and will be moved to a permanent, public place in the near
-// future.
+// future. This class object is created, destructed and operated on the UI
+// thread.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERIES_PRIVATE_MEDIA_GALLERIES_PRIVATE_EVENT_ROUTER_H_
 #define CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERIES_PRIVATE_MEDIA_GALLERIES_PRIVATE_EVENT_ROUTER_H_
 
+#include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/system_monitor/system_monitor.h"
-#include "base/values.h"
+#include "base/threading/thread_checker.h"
 
+class FilePath;
 class Profile;
 
+namespace base {
+class ListValue;
+}
+
 namespace extensions {
 
 class MediaGalleriesPrivateEventRouter
@@ -27,6 +34,10 @@ class MediaGalleriesPrivateEventRouter
   explicit MediaGalleriesPrivateEventRouter(Profile* profile);
   virtual ~MediaGalleriesPrivateEventRouter();
 
+  // Gallery changed event handler.
+  void OnGalleryChanged(const std::string& gallery_id,
+                        const std::set<std::string>& extension_ids);
+
  private:
   // base::SystemMonitor::DevicesChangedObserver implementation.
   virtual void OnRemovableStorageAttached(
@@ -38,8 +49,12 @@ class MediaGalleriesPrivateEventRouter
   void DispatchEvent(const std::string& event_name,
                      scoped_ptr<base::ListValue> event_args);
 
+  // Current profile.
   Profile* profile_;
 
+  // Make sure all the member functions are called on the right thread.
+  base::ThreadChecker thread_checker_;
+
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesPrivateEventRouter);
 };