content: Remove Lock/Unlock CompositingSurface API from RWH.

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index c282dd95ac9227e4aa9d47a82c14f214928135e0..e840fa89c6edf6ab588edae9b4e3b70fa264e1c4 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -833,16 +833,6 @@ bool RenderWidgetHostImpl::CanCopyFromBackingStore() {
   return false;
 }
 
-void RenderWidgetHostImpl::LockBackingStore() {
-  if (view_)
-    view_->LockCompositingSurface();
-}
-
-void RenderWidgetHostImpl::UnlockBackingStore() {
-  if (view_)
-    view_->UnlockCompositingSurface();
-}
-
 #if defined(OS_MACOSX)
 void RenderWidgetHostImpl::PauseForPendingResizeOrRepaints() {
   TRACE_EVENT0("browser",