Implement languagechange event, fired when accept languages changes.

Source/core/page/Page.cpp

Index: Source/core/page/Page.cpp
diff --git a/Source/core/page/Page.cpp b/Source/core/page/Page.cpp
index d2cbc0d8e4f6ee0c6fe3d5fd05f9c4b982a4f767..69e6994589f8b1eb3709670fb90bb923f99b5075 100644
--- a/Source/core/page/Page.cpp
+++ b/Source/core/page/Page.cpp
@@ -531,6 +531,17 @@ void Page::didCommitLoad(LocalFrame* frame)
     }
 }
 
+void Page::acceptLanguagesChanged()
+{
+    Vector< RefPtr<LocalFrame> > frames;
+
+    for (LocalFrame* frame = mainFrame(); frame; frame = frame->tree().traverseNext())
+        frames.append(frame);
+
+    for (unsigned i = 0; i < frames.size(); ++i)
+        frames[i]->domWindow()->dispatchEvent(Event::create(EventTypeNames::languagechange));
+}
+
 PageLifecycleNotifier& Page::lifecycleNotifier()
 {
     return static_cast<PageLifecycleNotifier&>(LifecycleContext<Page>::lifecycleNotifier());