Remove mainthread overhang painting code

Source/web/WebPluginContainerImpl.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2014 Opera Software ASA. 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.
@@ skipping 681 matching lines @@
     if (m_scrollbarGroup)
         m_scrollbarGroup->willStartLiveResize();
 }
 
 void WebPluginContainerImpl::willEndLiveResize()
 {
     if (m_scrollbarGroup)
         m_scrollbarGroup->willEndLiveResize();
 }
 
-bool WebPluginContainerImpl::paintCustomOverhangArea(GraphicsContext* context, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect)
-{
-    Color fillColor(0xCC, 0xCC, 0xCC);
-    context->fillRect(intersection(horizontalOverhangArea, dirtyRect), fillColor);
-    context->fillRect(intersection(verticalOverhangArea, dirtyRect), fillColor);
-    return true;
-}
-
 // Private methods -------------------------------------------------------------
 
 WebPluginContainerImpl::WebPluginContainerImpl(HTMLPlugInElement* element, WebPlugin* webPlugin)
     : LocalFrameLifecycleObserver(element->document().frame())
     , m_element(element)
     , m_webPlugin(webPlugin)
     , m_webLayer(nullptr)
     , m_isInPaint(false)
     , m_touchEventRequestType(TouchEventRequestTypeNone)
     , m_wantsWheelEvents(false)
@@ skipping 299 matching lines @@
     for (size_t i = 0; i < cutOutRects.size(); i++)
         cutOutRects[i].move(-frameRect().x(), -frameRect().y());
 }
 
 bool WebPluginContainerImpl::pluginShouldPersist() const
 {
     return m_webPlugin->shouldPersist();
 }
 
 } // namespace blink