Implement languagechange event, fired when accept languages changes.

Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 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 244 matching lines @@
     virtual void addPageOverlay(WebPageOverlay*, int /* zOrder */) OVERRIDE;
     virtual void removePageOverlay(WebPageOverlay*) OVERRIDE;
     virtual void transferActiveWheelFlingAnimation(const WebActiveWheelFlingParameters&) OVERRIDE;
     virtual bool endActiveFlingAnimation() OVERRIDE;
     virtual void setShowPaintRects(bool) OVERRIDE;
     void setShowDebugBorders(bool);
     virtual void setShowFPSCounter(bool) OVERRIDE;
     virtual void setContinuousPaintingEnabled(bool) OVERRIDE;
     virtual void setShowScrollBottleneckRects(bool) OVERRIDE;
     virtual void getSelectionRootBounds(WebRect& bounds) const OVERRIDE;
+    virtual void acceptLanguagesChanged() OVERRIDE;
 
     // WebViewImpl
 
     void suppressInvalidations(bool enable);
     void invalidateRect(const WebCore::IntRect&);
 
     void setIgnoreInputEvents(bool newValue);
     void setBackgroundColorOverride(WebColor);
     void setZoomFactorOverride(float);
     WebDevToolsAgentPrivate* devToolsAgentPrivate() { return m_devToolsAgent.get(); }
@@ skipping 455 matching lines @@
     bool m_userGestureObserved;
 };
 
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 } // namespace blink
 
 #endif