Remove the WebSetting for deferred image decode.

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 526 matching lines @@
 void WebSettingsImpl::setAntialiased2dCanvasEnabled(bool enabled)
 {
     m_settings->setAntialiased2dCanvasEnabled(enabled);
 }
 
 void WebSettingsImpl::setAntialiasedClips2dCanvasEnabled(bool enabled)
 {
     m_settings->setAntialiasedClips2dCanvasEnabled(enabled);
 }
 
-void WebSettingsImpl::setDeferredImageDecodingEnabled(bool enabled)
-{
-}
-
 void WebSettingsImpl::setPreferCompositingToLCDTextEnabled(bool enabled)
 {
     m_devToolsEmulator->setPreferCompositingToLCDTextEnabled(enabled);
 }
 
 void WebSettingsImpl::setMinimumAccelerated2dCanvasSize(int numPixels)
 {
     m_settings->setMinimumAccelerated2dCanvasSize(numPixels);
 }
 
@@ skipping 227 matching lines @@
 {
     m_settings->setV8CacheOptions(static_cast<blink::V8CacheOptions>(options));
 }
 
 void WebSettingsImpl::setUseMobileViewportStyle(bool enabled)
 {
     m_devToolsEmulator->setUseMobileViewportStyle(enabled);
 }
 
 } // namespace blink