Remove media_galleries_handlers - not used.

chrome/common/extensions/api/media_galleries_private.idl

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is a private API since M23. Gallery watching needs to be implemented
 // on platforms others than Windows and then moved to the public API.
 // See http://crbug.com/166950.
 namespace mediaGalleriesPrivate {
   // A dictionary that describes the modified gallery.
   [inline_doc] dictionary GalleryChangeDetails {
     // Gallery identifier.
     DOMString galleryId;
   };
 
   interface Events {
     // Fired when a media gallery is changed.
     static void onGalleryChanged(GalleryChangeDetails details);
   };
 
   // A dictionary that describes the add gallery watch request results.
   dictionary AddGalleryWatchResult {
     DOMString galleryId;
     boolean success;
   };
 
   callback AddGalleryWatchCallback = void (AddGalleryWatchResult result);
   callback GetAllGalleryWatchCallback = void (DOMString[] galleryIds);
 
-  // A dictionary that describes a media galleries handler.
-  [inline_doc] dictionary MediaGalleriesHandler {
-    // Unique action id per extension.
-    DOMString id;
-
-    // ID of the extension handling this handler.
-    DOMString extensionId;
-
-    // Localized title describing the action.
-    DOMString title;
-
-    // Url of the icon.
-    DOMString iconUrl;
-  };
-
-  callback GetHandlersCallback = void (MediaGalleriesHandler[] handlers);
-
   interface Functions {
     static void addGalleryWatch(DOMString galleryId,
                                 AddGalleryWatchCallback callback);
     static void removeGalleryWatch(DOMString galleryId);
     static void getAllGalleryWatch(GetAllGalleryWatchCallback callback);
     static void removeAllGalleryWatch();
-    static void getHandlers(GetHandlersCallback callback);
   };
 };