Remove the forceCompositingMode setting.

Source/web/WebSettingsImpl.cpp

 /*
  * 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 407 matching lines @@
 {
     m_settings->setEditingBehaviorType(static_cast<WebCore::EditingBehaviorType>(behavior));
 }
 
 void WebSettingsImpl::setAcceleratedCompositingEnabled(bool enabled)
 {
     m_settings->setAcceleratedCompositingEnabled(enabled);
     m_settings->setScrollingCoordinatorEnabled(enabled);
 }
 
-void WebSettingsImpl::setForceCompositingMode(bool enabled)
-{
-    m_settings->setForceCompositingMode(enabled);
-}
-
 void WebSettingsImpl::setMockScrollbarsEnabled(bool enabled)
 {
     m_settings->setMockScrollbarsEnabled(enabled);
 }
 
 void WebSettingsImpl::setAcceleratedCompositingForFiltersEnabled(bool enabled)
 {
     m_settings->setAcceleratedCompositingForFiltersEnabled(enabled);
 }
 
@@ skipping 262 matching lines @@
 {
     m_settings->setUseSolidColorScrollbars(enabled);
 }
 
 void WebSettingsImpl::setMainFrameResizesAreOrientationChanges(bool enabled)
 {
     m_mainFrameResizesAreOrientationChanges = enabled;
 }
 
 } // namespace blink