Media galleries: configuration dialog controller and GTK impl.

chrome/browser/extensions/api/media_galleries/media_galleries_api.h

Index: chrome/browser/extensions/api/media_galleries/media_galleries_api.h
diff --git a/chrome/browser/extensions/api/media_galleries/media_galleries_api.h b/chrome/browser/extensions/api/media_galleries/media_galleries_api.h
index 45b7e6e1627df8f3180d8edae648c4a63c0c1094..51ba4b37c7dfd8e705f70e6be0d9ca3813281db2 100644
--- a/chrome/browser/extensions/api/media_galleries/media_galleries_api.h
+++ b/chrome/browser/extensions/api/media_galleries/media_galleries_api.h
@@ -12,7 +12,8 @@
 
 namespace extensions {
 
-class MediaGalleriesGetMediaFileSystemsFunction : public SyncExtensionFunction {
+class MediaGalleriesGetMediaFileSystemsFunction
+    : public AsyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME(
       "experimental.mediaGalleries.getMediaFileSystems")
@@ -20,6 +21,13 @@ class MediaGalleriesGetMediaFileSystemsFunction : public SyncExtensionFunction {
  protected:
   virtual ~MediaGalleriesGetMediaFileSystemsFunction();
   virtual bool RunImpl() OVERRIDE;
+
+ private:
+  // Grabs the galleries from the preferences system and returns them.
+  void ReturnGalleries();
+
+  // Shows the configuration dialog to edit gallery preferences.
+  void ShowDialog();
 };
 
 class MediaGalleriesAssembleMediaFileFunction : public SyncExtensionFunction {