Expose locks for CopyFromCompositingSurface/CopyFromBackingStore API

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 748aa48bb3f9052d0d3c8a4c17a6062dbba9407f..828df2308fcb7ef6e84c19ca9e3e6c84877c5e95 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -742,6 +742,24 @@ void RenderWidgetHostImpl::CopyFromBackingStore(
   callback.Run(result, output.GetBitmap());
 }
 
+bool RenderWidgetHostImpl::CanCopyFromBackingStore() {
+  if (view_)
+    return view_->IsSurfaceAvailableForCopy();
+  return false;
+}
+
+#if defined(OS_ANDROID)
+void RenderWidgetHostImpl::LockBackingStore() {
+  if (view_)
+    view_->LockCompositingSurface();
+}
+
+void RenderWidgetHostImpl::UnlockBackingStore() {
+  if (view_)
+    view_->UnlockCompositingSurface();
+}
+#endif
+
 #if defined(TOOLKIT_GTK)
 bool RenderWidgetHostImpl::CopyFromBackingStoreToGtkWindow(
     const gfx::Rect& dest_rect, GdkWindow* target) {