chrome: Cleanup class/struct forward declarations

chrome/browser/media/extension_media_access_handler.h

 // Copyright 2015 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_MEDIA_EXTENSION_MEDIA_ACCESS_HANDLER_H_
 #define CHROME_BROWSER_MEDIA_EXTENSION_MEDIA_ACCESS_HANDLER_H_
 
 #include "chrome/browser/media/media_access_handler.h"
 
-class MediaStreamCaptureIndicator;
-
 // MediaAccessHandler for extension capturing requests.
 class ExtensionMediaAccessHandler : public MediaAccessHandler {
  public:
   ExtensionMediaAccessHandler();
   ~ExtensionMediaAccessHandler() override;
 
   // MediaAccessHandler implementation.
   bool SupportsStreamType(const content::MediaStreamType type,
                           const extensions::Extension* extension) override;
   bool CheckMediaAccessPermission(
       content::WebContents* web_contents,
       const GURL& security_origin,
       content::MediaStreamType type,
       const extensions::Extension* extension) override;
   void HandleRequest(content::WebContents* web_contents,
                      const content::MediaStreamRequest& request,
                      const content::MediaResponseCallback& callback,
                      const extensions::Extension* extension) override;
 };
 
 #endif  // CHROME_BROWSER_MEDIA_EXTENSION_MEDIA_ACCESS_HANDLER_H_