Revert of [Extensions] Don't count bubble dismissal from focus loss as acknowledgment

chrome/browser/extensions/ntp_overridden_bubble_delegate.h

 // Copyright (c) 2014 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_EXTENSIONS_NTP_OVERRIDDEN_BUBBLE_DELEGATE_H_
 #define CHROME_BROWSER_EXTENSIONS_NTP_OVERRIDDEN_BUBBLE_DELEGATE_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 21 matching lines @@
       const base::string16& overflow_count) const override;
   GURL GetLearnMoreUrl() const override;
   base::string16 GetActionButtonLabel() const override;
   base::string16 GetDismissButtonLabel() const override;
   bool ShouldCloseOnDeactivate() const override;
   bool ShouldShowExtensionList() const override;
   bool ShouldHighlightExtensions() const override;
   bool ShouldLimitToEnabledExtensions() const override;
   void LogExtensionCount(size_t count) override;
   void LogAction(ExtensionMessageBubbleController::BubbleAction) override;
-  const char* GetKey() override;
 
  private:
   // The ID of the extension we are showing the bubble for.
   std::string extension_id_;
 
   DISALLOW_COPY_AND_ASSIGN(NtpOverriddenBubbleDelegate);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_NTP_OVERRIDDEN_BUBBLE_DELEGATE_H_