Maintain minimal error response.

content/browser/renderer_host/render_widget_host_impl.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_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 698 matching lines @@
 
   // TODO(evanm): tracking this may no longer be necessary;
   // eliminate this function if so.
   SetView(NULL);
 }
 
 void RenderWidgetHostImpl::CopyFromBackingStore(
     const gfx::Rect& src_subrect,
     const gfx::Size& accelerated_dst_size,
     ReadbackRequestCallback& callback,
-    const SkColorType color_type) {
+    const SkColorType preferred_color_type) {
   if (view_) {
     TRACE_EVENT0("browser",
         "RenderWidgetHostImpl::CopyFromBackingStore::FromCompositingSurface");
     gfx::Rect accelerated_copy_rect = src_subrect.IsEmpty() ?
         gfx::Rect(view_->GetViewBounds().size()) : src_subrect;
-    view_->CopyFromCompositingSurface(
-        accelerated_copy_rect, accelerated_dst_size, callback, color_type);
+    view_->CopyFromCompositingSurface(accelerated_copy_rect,
+                                      accelerated_dst_size, callback,
+                                      preferred_color_type);
     return;
   }
 
   callback.Run(SkBitmap(), content::READBACK_FAILED);
 }
 
 bool RenderWidgetHostImpl::CanCopyFromBackingStore() {
   if (view_)
     return view_->IsSurfaceAvailableForCopy();
   return false;
@@ skipping 1377 matching lines @@
   return latency_tracker_.GetEstimatedBrowserCompositeTime();
 }
 
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
     RenderWidgetHostImpl::GetParentNativeViewAccessible() {
   return delegate_ ? delegate_->GetParentNativeViewAccessible() : NULL;
 }
 #endif
 
-SkColorType RenderWidgetHostImpl::PreferredReadbackFormat() {
-  if (view_)
-    return view_->PreferredReadbackFormat();
-  return kN32_SkColorType;
-}
-
 }  // namespace content