Add RGB565 Texture readback support in gl_helper

content/browser/renderer_host/render_widget_host_view_gtk.cc

 // 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.
 
 #include "content/browser/renderer_host/render_widget_host_view_gtk.h"
 
 #include <cairo/cairo.h>
 #include <gdk/gdk.h>
 #include <gdk/gdkkeysyms.h>
 #include <gdk/gdkx.h>
@@ skipping 1029 matching lines @@
   return new BackingStoreGtk(host_, size,
                              ui::GetVisualFromGtkWidget(view_.get()),
                              depth);
 }
 
 // NOTE: |output| is initialized with the size of |src_subrect|, and |dst_size|
 // is ignored on GTK.
 void RenderWidgetHostViewGtk::CopyFromCompositingSurface(
     const gfx::Rect& src_subrect,
     const gfx::Size& /* dst_size */,
-    const base::Callback<void(bool, const SkBitmap&)>& callback) {
+    const base::Callback<void(bool, const SkBitmap&)>& callback,
+    bool readback_config_rgb565) {
+  if (readback_config_rgb565) {
+    NOTIMPLEMENTED();
+    callback.Run(false, SkBitmap());
+  }
   // Grab the snapshot from the renderer as that's the only reliable way to
   // readback from the GPU for this platform right now.
   GetRenderWidgetHost()->GetSnapshotFromRenderer(src_subrect, callback);
 }
 
 void RenderWidgetHostViewGtk::CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,
       const base::Callback<void(bool)>& callback) {
   NOTIMPLEMENTED();
@@ skipping 540 matching lines @@
     gfx::PluginWindowHandle id) {
   plugin_container_manager_.CreatePluginContainer(id);
 }
 
 void RenderWidgetHostViewGtk::OnDestroyPluginContainer(
     gfx::PluginWindowHandle id) {
   plugin_container_manager_.DestroyPluginContainer(id);
 }
 
 }  // namespace content