Implement languagechange event, fired when accept languages changes.

Source/web/WebViewImpl.cpp

 /*
  * Copyright (C) 2011, 2012 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 890 matching lines @@
         ? IntRect(IntPoint(0, 0), root->document().frame()->view()->contentsSize())
         : root->pixelSnappedBoundingBox();
 
     boundingBox = root->document().frame()->view()->contentsToWindow(boundingBox);
     boundingBox.scale(pageScaleFactor());
     bounds = boundingBox;
 }
 
 void WebViewImpl::acceptLanguagesChanged()
 {
+    if (!page())
+        return;
+
+    page()->acceptLanguagesChanged();
 }
 
 bool WebViewImpl::handleKeyEvent(const WebKeyboardEvent& event)
 {
     ASSERT((event.type == WebInputEvent::RawKeyDown)
         || (event.type == WebInputEvent::KeyDown)
         || (event.type == WebInputEvent::KeyUp));
 
     // Halt an in-progress fling on a key event.
     endActiveFlingAnimation();
@@ skipping 3158 matching lines @@
     const PageScaleConstraints& constraints = m_pageScaleConstraintsSet.pageDefinedConstraints();
 
     if (!mainFrameImpl() || !mainFrameImpl()->frameView())
         return false;
 
     return mainFrameImpl()->frameView()->layoutSize().width() == m_size.width
         || (constraints.minimumScale == constraints.maximumScale && constraints.minimumScale != -1);
 }
 
 } // namespace blink