Make DrawingBuffer and Canvas2DLayerBridge be cc::TextureLayerClients.

third_party/WebKit/public/blink_headers.gypi

 # Copyright 2015 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.
 
 {
   'variables': {
     'blink_public_sources': [
       "platform/callback/WebClosure.h",
       "platform/Platform.h",
       "platform/FilePathConversion.h",
@@ skipping 53 matching lines @@
       "platform/WebDragData.h",
       "platform/WebDragOperation.h",
       'platform/WebEditingCommandType.h',
       "platform/WebEffectiveConnectionType.h",
       "platform/WebEncryptedMediaClient.h",
       "platform/WebEncryptedMediaKeyInformation.h",
       "platform/WebEncryptedMediaRequest.h",
       "platform/WebEncryptedMediaTypes.h",
       "platform/WebExternalBitmap.h",
       "platform/WebExternalTextureLayer.h",
-      "platform/WebExternalTextureLayerClient.h",
-      "platform/WebExternalTextureMailbox.h",
       "platform/WebFallbackThemeEngine.h",
       "platform/WebFederatedCredential.h",
       "platform/WebFileError.h",
       "platform/WebFileInfo.h",
       "platform/WebFileSystem.h",
       "platform/WebFileSystemCallbacks.h",
       "platform/WebFileSystemEntry.h",
       "platform/WebFileSystemType.h",
       "platform/WebFileUtilities.h",
       "platform/WebFileWriter.h",
@@ skipping 398 matching lines @@
       "web/mac/WebScrollbarTheme.h",
       "web/mac/WebSubstringUtil.h",
       "web/modules/notifications/WebNotificationPermissionCallback.h",
       "web/modules/serviceworker/WebServiceWorkerContextClient.h",
       "web/modules/serviceworker/WebServiceWorkerContextProxy.h",
       "web/modules/serviceworker/WebServiceWorkerNetworkProvider.h",
       "web/win/WebFontRendering.h",
     ],
   },
 }