Add a "Learn More" link to the Spelling bubble.

chrome/browser/tab_contents/spelling_bubble_model.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_TAB_CONTENTS_SPELLING_BUBBLE_MODEL_H_
 #define CHROME_BROWSER_TAB_CONTENTS_SPELLING_BUBBLE_MODEL_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/string16.h"
 #include "chrome/browser/ui/confirm_bubble_model.h"
 
 class Profile;
 
 // A class that implements a bubble menu shown when we confirm a user allows
 // integrating the spelling service of Google to Chrome.
 class SpellingBubbleModel : public ConfirmBubbleModel {
  public:
   explicit SpellingBubbleModel(Profile* profile);
   virtual ~SpellingBubbleModel();
 
   // ConfirmBubbleModel implementation.
   virtual string16 GetTitle() const OVERRIDE;
   virtual string16 GetMessageText() const OVERRIDE;
   virtual gfx::Image* GetIcon() const OVERRIDE;
   virtual string16 GetButtonLabel(BubbleButton button) const OVERRIDE;
   virtual void Accept() OVERRIDE;
   virtual void Cancel() OVERRIDE;
+  virtual string16 GetLinkText() const OVERRIDE;
+  virtual void LinkClicked() OVERRIDE;
 
  private:
   Profile* profile_;
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_SPELLING_BUBBLE_MODEL_H_