Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

content/browser/renderer_host/renderer_frame_manager.cc

Index: content/browser/renderer_host/renderer_frame_manager.cc
diff --git a/content/browser/renderer_host/renderer_frame_manager.cc b/content/browser/renderer_host/renderer_frame_manager.cc
index 15c9814d61075f032ec5d3196f6eec2071c573d5..0c3ac6b61a24a6316e4a1d2b9f4b77f638ce0888 100644
--- a/content/browser/renderer_host/renderer_frame_manager.cc
+++ b/content/browser/renderer_host/renderer_frame_manager.cc
@@ -26,15 +26,14 @@ void RendererFrameManager::AddFrame(RendererFrameManagerClient* frame,
 }
 
 void RendererFrameManager::RemoveFrame(RendererFrameManagerClient* frame) {
-  std::map<RendererFrameManagerClient*, size_t>::iterator locked_iter =
-      locked_frames_.find(frame);
+  LockedFrameCount::iterator locked_iter = locked_frames_.find(frame);
   if (locked_iter != locked_frames_.end())
     locked_frames_.erase(locked_iter);
   unlocked_frames_.remove(frame);
 }
 
 void RendererFrameManager::LockFrame(RendererFrameManagerClient* frame) {
-  std::list<RendererFrameManagerClient*>::iterator unlocked_iter =
+  UnlockedFrames::iterator unlocked_iter =
     std::find(unlocked_frames_.begin(), unlocked_frames_.end(), frame);
   if (unlocked_iter != unlocked_frames_.end()) {
     DCHECK(locked_frames_.find(frame) == locked_frames_.end());
@@ -59,6 +58,13 @@ void RendererFrameManager::UnlockFrame(RendererFrameManagerClient* frame) {
   }
 }
 
+size_t RendererFrameManager::LockedCount(RendererFrameManagerClient* frame) {
+  LockedFrameCount::iterator iter = locked_frames_.find(frame);
+  if (iter != locked_frames_.end())
+    return iter->second;
+  return 0;
+}
+
 RendererFrameManager::RendererFrameManager() {
   max_number_of_saved_frames_ =
 #if defined(OS_ANDROID)