Add support for accelerated fixed root background

Tools/DumpRenderTree/chromium/TestShell.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 92 matching lines @@
     : m_testIsPending(false)
     , m_testIsPreparing(false)
     , m_focusedWidget(0)
     , m_devTools(0)
     , m_dumpPixelsForCurrentTest(false)
     , m_allowExternalPages(false)
     , m_acceleratedCompositingForVideoEnabled(false)
     , m_acceleratedCompositingForFixedPositionEnabled(false)
     , m_acceleratedCompositingForOverflowScrollEnabled(false)
     , m_acceleratedCompositingForTransitionEnabled(false)
+    , m_acceleratedCompositingForFixedRootBackgroundEnabled(false)
     , m_softwareCompositingEnabled(false)
     , m_threadedCompositingEnabled(false)
     , m_forceCompositingMode(false)
     , m_threadedHTMLParser(true)
     , m_accelerated2dCanvasEnabled(false)
     , m_perTilePaintingEnabled(false)
     , m_deferredImageDecodingEnabled(false)
     , m_stressOpt(false)
     , m_stressDeopt(false)
     , m_dumpWhenFinished(true)
@@ skipping 83 matching lines @@
 }
 
 void TestShell::resetWebSettings(WebView& webView)
 {
     m_prefs.reset();
     m_prefs.acceleratedCompositingEnabled = true;
     m_prefs.acceleratedCompositingForVideoEnabled = m_acceleratedCompositingForVideoEnabled;
     m_prefs.acceleratedCompositingForFixedPositionEnabled = m_acceleratedCompositingForFixedPositionEnabled;
     m_prefs.acceleratedCompositingForOverflowScrollEnabled = m_acceleratedCompositingForOverflowScrollEnabled;
     m_prefs.acceleratedCompositingForTransitionEnabled = m_acceleratedCompositingForTransitionEnabled;
+    m_prefs.acceleratedCompositingForFixedRootBackgroundEnabled = m_acceleratedCompositingForFixedRootBackgroundEnabled;
     m_prefs.forceCompositingMode = m_forceCompositingMode;
     m_prefs.accelerated2dCanvasEnabled = m_accelerated2dCanvasEnabled;
     m_prefs.perTilePaintingEnabled = m_perTilePaintingEnabled;
     m_prefs.deferredImageDecodingEnabled = m_deferredImageDecodingEnabled;
     m_prefs.threadedHTMLParser = m_threadedHTMLParser;
     m_prefs.applyTo(&webView);
 }
 
 void TestShell::runFileTest(const TestParams& params, bool shouldDumpPixels)
 {
@@ skipping 328 matching lines @@
     for (size_t index = 0; index < entryCount; ++index) {
         WebHistoryItem historyItem = navigationController.entryAtIndex(index)->contentState();
         if (historyItem.isNull()) {
             historyItem.initialize();
             historyItem.setURLString(navigationController.entryAtIndex(index)->URL().spec().utf16());
         }
         result[index] = historyItem;
     }
     history->swap(result);
 }