chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/suspicious_extension_bubble_delegate.h

 // Copyright (c) 2013 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_SUSPICIOUS_EXTENSION_BUBBLE_DELEGATE_H_
 #define CHROME_BROWSER_EXTENSIONS_SUSPICIOUS_EXTENSION_BUBBLE_DELEGATE_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "chrome/browser/extensions/extension_message_bubble_controller.h"
 
-class Browser;
-
 namespace extensions {
 
 class SuspiciousExtensionBubbleDelegate
     : public ExtensionMessageBubbleController::Delegate {
  public:
   explicit SuspiciousExtensionBubbleDelegate(Profile* profile);
   ~SuspiciousExtensionBubbleDelegate() override;
 
   // ExtensionMessageBubbleController::Delegate methods.
   bool ShouldIncludeExtension(const extensions::Extension* extension) override;
@@ skipping 18 matching lines @@
   const char* GetKey() override;
   bool SupportsPolicyIndicator() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SuspiciousExtensionBubbleDelegate);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_SUSPICIOUS_EXTENSION_BUBBLE_DELEGATE_H_