Revert of Blend background with existing content

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 611 matching lines @@
 void WebSettingsImpl::setPerTilePaintingEnabled(bool enabled)
 {
     m_perTilePaintingEnabled = enabled;
 }
 
 void WebSettingsImpl::setShouldPrintBackgrounds(bool enabled)
 {
     m_settings->setShouldPrintBackgrounds(enabled);
 }
 
-void WebSettingsImpl::setShouldClearDocumentBackground(bool enabled)
-{
-    m_settings->setShouldClearDocumentBackground(enabled);
-}
-
 void WebSettingsImpl::setEnableScrollAnimator(bool enabled)
 {
     m_settings->setScrollAnimatorEnabled(enabled);
 }
 
 void WebSettingsImpl::setEnableTouchAdjustment(bool enabled)
 {
     m_settings->setTouchAdjustmentEnabled(enabled);
 }
 
@@ skipping 126 matching lines @@
 {
     m_settings->setUseSolidColorScrollbars(enabled);
 }
 
 void WebSettingsImpl::setMainFrameResizesAreOrientationChanges(bool enabled)
 {
     m_mainFrameResizesAreOrientationChanges = enabled;
 }
 
 } // namespace blink