[Attempt 2] Inform Chrome client of changes to an input's datalist.

Source/web/ChromeClientImpl.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * 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.
@@ skipping 152 matching lines @@
     virtual void requestPointerUnlock() override;
 
     virtual bool shouldDisableDesktopWorkarounds() override;
 
     // AutofillClient pass throughs:
     virtual void didAssociateFormControls(const WillBeHeapVector<RefPtrWillBeMember<Element> >&, LocalFrame*) override;
     virtual void handleKeyboardEventOnTextField(HTMLInputElement&, KeyboardEvent&) override;
     virtual void didChangeValueInTextField(HTMLFormControlElement&) override;
     virtual void didEndEditingOnTextField(HTMLInputElement&) override;
     virtual void openTextDataListChooser(HTMLInputElement&) override;
+    virtual void textFieldDataListChanged(HTMLInputElement&) override;
 
     virtual void didCancelCompositionOnSelectionChange() override;
     virtual void willSetInputMethodState() override;
     virtual void didUpdateTextOfFocusedElementByNonUserInput() override;
     virtual void showImeIfNeeded() override;
 
 private:
     virtual bool isChromeClientImpl() const override { return true; }
 
     WebNavigationPolicy getNavigationPolicy(const WindowFeatures&);
     void setCursor(const WebCursorInfo&);
 
     WebViewImpl* m_webView;  // weak pointer
     WindowFeatures m_windowFeatures;
 
     PagePopupDriver* m_pagePopupDriver;
 };
 
 DEFINE_TYPE_CASTS(ChromeClientImpl, ChromeClient, client, client->isChromeClientImpl(), client.isChromeClientImpl());
 
 } // namespace blink
 
 #endif