content: Remove Lock/Unlock CompositingSurface API from RWH.

content/browser/frame_host/render_widget_host_view_child_frame.cc

Index: content/browser/frame_host/render_widget_host_view_child_frame.cc
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame.cc b/content/browser/frame_host/render_widget_host_view_child_frame.cc
index e87dde217bd086fd86ec7c4ab105c48881e9fe97..2ffeeb18248006d6f9162a099bea60e4329f50fd 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame.cc
+++ b/content/browser/frame_host/render_widget_host_view_child_frame.cc
@@ -303,14 +303,6 @@ void RenderWidgetHostViewChildFrame::SetTooltipText(
   frame_connector_->GetRootRenderWidgetHostView()->SetTooltipText(tooltip_text);
 }
 
-void RenderWidgetHostViewChildFrame::LockCompositingSurface() {
-  NOTIMPLEMENTED();
-}
-
-void RenderWidgetHostViewChildFrame::UnlockCompositingSurface() {
-  NOTIMPLEMENTED();
-}
-
 RenderWidgetHostViewBase* RenderWidgetHostViewChildFrame::GetParentView() {
   if (!frame_connector_)
     return nullptr;