Remove the forceCompositingMode setting.

Source/web/WebPagePopupImpl.cpp

 /*
  * Copyright (C) 2012 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 279 matching lines @@
 WebSize WebPagePopupImpl::size()
 {
     return m_popupClient->contentSize();
 }
 
 void WebPagePopupImpl::animate(double)
 {
     PageWidgetDelegate::animate(m_page.get(), monotonicallyIncreasingTime());
 }
 
-void WebPagePopupImpl::enterForceCompositingMode(bool enter)
-{
-    if (!m_page)
-        return;
-    if (m_page->settings().forceCompositingMode() == enter)
-        return;
-
-    TRACE_EVENT1("webkit", "WebPagePopupImpl::enterForceCompositingMode", "enter", enter);
-    m_page->settings().setForceCompositingMode(enter);
-    if (enter) {
-        LocalFrame* mainFrame = m_page->mainFrame();
-        if (!mainFrame)
-            return;
-        mainFrame->view()->updateCompositingLayersAfterStyleChange();
-    }
-}
-
 void WebPagePopupImpl::willCloseLayerTreeView()
 {
     setIsAcceleratedCompositingActive(false);
     m_layerTreeView = 0;
 }
 
 void WebPagePopupImpl::layout()
 {
     PageWidgetDelegate::layout(m_page.get());
 }
@@ skipping 96 matching lines @@
     // A WebPagePopupImpl instance usually has two references.
     //  - One owned by the instance itself. It represents the visible widget.
     //  - One owned by a WebViewImpl. It's released when the WebViewImpl ask the
     //    WebPagePopupImpl to close.
     // We need them because the closing operation is asynchronous and the widget
     // can be closed while the WebViewImpl is unaware of it.
     return adoptRef(new WebPagePopupImpl(client)).leakRef();
 }
 
 } // namespace blink