Maintain minimal error response.

content/browser/frame_host/render_widget_host_view_child_frame.cc

 // Copyright 2014 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/frame_host/render_widget_host_view_child_frame.h"
 
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/common/gpu/gpu_messages.h"
@@ skipping 244 matching lines @@
 bool RenderWidgetHostViewChildFrame::PostProcessEventForPluginIme(
       const NativeWebKeyboardEvent& event) {
   return false;
 }
 #endif // defined(OS_MACOSX)
 
 void RenderWidgetHostViewChildFrame::CopyFromCompositingSurface(
     const gfx::Rect& src_subrect,
     const gfx::Size& /* dst_size */,
     ReadbackRequestCallback& callback,
     const SkColorType color_type) {

[no sievers, 2015/05/06 23:08:03]

Should we rename this to |preferred_color_type| then here and everywhere?

[sivag, 2015/05/07 14:14:20]

Done.

-  callback.Run(SkBitmap(), READBACK_NOT_SUPPORTED);
+  callback.Run(SkBitmap(), READBACK_FAILED);
 }
 
 void RenderWidgetHostViewChildFrame::CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,
       const base::Callback<void(bool)>& callback) {
   NOTIMPLEMENTED();
   callback.Run(false);
 }
 
@@ skipping 26 matching lines @@
 }
 
 BrowserAccessibilityManager*
 RenderWidgetHostViewChildFrame::CreateBrowserAccessibilityManager(
     BrowserAccessibilityDelegate* delegate) {
   return BrowserAccessibilityManager::Create(
       BrowserAccessibilityManager::GetEmptyDocument(), delegate);
 }
 
 }  // namespace content