content: Remove Lock/Unlock CompositingSurface API from RWH.

content/browser/renderer_host/render_widget_host_view_base.h

Index: content/browser/renderer_host/render_widget_host_view_base.h
diff --git a/content/browser/renderer_host/render_widget_host_view_base.h b/content/browser/renderer_host/render_widget_host_view_base.h
index f78bc0b8de7c20659b427a74e56d5615220f41ce..b7e0cda7766034cfe42ee7698329d66fe6aefed0 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.h
+++ b/content/browser/renderer_host/render_widget_host_view_base.h
@@ -409,10 +409,6 @@ class CONTENT_EXPORT RenderWidgetHostViewBase : public RenderWidgetHostView,
   // main frame.
   virtual void OnDidNavigateMainFrameToNewPage();
 
-  // Instructs the view to not drop the surface even when the view is hidden.
-  virtual void LockCompositingSurface() = 0;
-  virtual void UnlockCompositingSurface() = 0;
-
   // Add and remove observers for lifetime event notifications. The order in
   // which notifications are sent to observers is undefined. Clients must be
   // sure to remove the observer before they go away.