Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

content/browser/renderer_host/delegated_frame_evictor.cc

 // Copyright 2013 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/delegated_frame_evictor.h"
 
 #include "base/logging.h"
 
 namespace content {
 
@@ skipping 30 matching lines @@
 
 void DelegatedFrameEvictor::UnlockFrame() {
   DCHECK(has_frame_);
   RendererFrameManager::GetInstance()->UnlockFrame(this);
 }
 
 void DelegatedFrameEvictor::EvictCurrentFrame() {
   client_->EvictDelegatedFrame();
 }
 
+bool DelegatedFrameEvictor::FrameLocked() {
+  // The first lock is the visible/invisible state.
+  return has_frame_ &&
+         RendererFrameManager::GetInstance()->LockedCount(this) > 1;
+}
+
 }  // namespace content