Scroll only visual viewport during OSX pinch gesture behind flag.

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 162 matching lines @@
 void WebSettingsImpl::setAccessibilityPasswordValuesEnabled(bool enabled)
 {
     m_settings->setAccessibilityPasswordValuesEnabled(enabled);
 }
 
 void WebSettingsImpl::setInlineTextBoxAccessibilityEnabled(bool enabled)
 {
     m_settings->setInlineTextBoxAccessibilityEnabled(enabled);
 }
 
+void WebSettingsImpl::setInvertViewportScrollOrder(bool enabled)
+{
+    m_settings->setInvertViewportScrollOrder(enabled);
+}
+
 void WebSettingsImpl::setDeviceScaleAdjustment(float deviceScaleAdjustment)
 {
     m_devToolsEmulator->setDeviceScaleAdjustment(deviceScaleAdjustment);
 }
 
 void WebSettingsImpl::setDefaultTextEncodingName(const WebString& encoding)
 {
     m_settings->setDefaultTextEncodingName((String)encoding);
 }
 
@@ skipping 591 matching lines @@
 {
     m_settings->setV8CacheOptions(static_cast<blink::V8CacheOptions>(options));
 }
 
 void WebSettingsImpl::setUseMobileViewportStyle(bool enabled)
 {
     m_devToolsEmulator->setUseMobileViewportStyle(enabled);
 }
 
 } // namespace blink