Declare a new name for CompositingSurface completion callback.

content/test/test_render_view_host.cc

Index: content/test/test_render_view_host.cc
diff --git a/content/test/test_render_view_host.cc b/content/test/test_render_view_host.cc
index dcc0051186222aae90d8be2b046d58f290214eee..1bece4c3ff5f312236ac7aa874d664b11795cf2c 100644
--- a/content/test/test_render_view_host.cc
+++ b/content/test/test_render_view_host.cc
@@ -111,7 +111,7 @@ gfx::Rect TestRenderWidgetHostView::GetViewBounds() const {
 void TestRenderWidgetHostView::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) {
   callback.Run(false, SkBitmap());
 }