Add support for Low Priorirty tasks.

public/web/WebWidget.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebWidget_h
 #define WebWidget_h
 
+#include "../platform/WebBeginFrameArgs.h"
 #include "../platform/WebCanvas.h"
 #include "../platform/WebCommon.h"
 #include "../platform/WebRect.h"
 #include "../platform/WebSize.h"
-#include "WebBeginFrameArgs.h"
 #include "WebCompositionUnderline.h"
 #include "WebTextDirection.h"
 #include "WebTextInputInfo.h"
 
 namespace blink {
 
 class WebCompositeAndReadbackAsyncCallback;
 class WebInputEvent;
 class WebLayerTreeView;
 class WebMouseEvent;
@@ skipping 205 matching lines @@
     // content.
     virtual WebColor backgroundColor() const { return 0xFFFFFFFF; /* SK_ColorWHITE */ }
 
 protected:
     ~WebWidget() { }
 };
 
 } // namespace blink
 
 #endif