Declare a new name for CompositingSurface completion callback.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 74e624ae9b386071ba1ab04cb5f6b721cbc84424..99b4bcf405b173dec47e770c7a6dac21c3b8a5be 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -941,7 +941,7 @@ void RenderWidgetHostViewAura::SelectionBoundsChanged(
 void RenderWidgetHostViewAura::CopyFromCompositingSurface(
     const gfx::Rect& src_subrect,
     const gfx::Size& dst_size,
-    const base::Callback<void(bool, const SkBitmap&)>& callback,
+    CompletionCallback& callback,
     const SkColorType color_type) {
   delegated_frame_host_->CopyFromCompositingSurface(
       src_subrect, dst_size, callback, color_type);