chrome: Cleanup class/struct forward declarations

chrome/browser/ui/webui/theme_source.h

 // Copyright (c) 2012 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_UI_WEBUI_THEME_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_THEME_SOURCE_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "content/public/browser/url_data_source.h"
 
 class Profile;
 
-namespace base {
-class RefCountedMemory;
-}
-
 class ThemeSource : public content::URLDataSource {
  public:
   explicit ThemeSource(Profile* profile);
   ~ThemeSource() override;
 
   // content::URLDataSource implementation.
   std::string GetSource() const override;
   void StartDataRequest(
       const std::string& path,
       const content::ResourceRequestInfo::WebContentsGetter& wc_getter,
@@ skipping 16 matching lines @@
                       int resource_id,
                       float scale);
 
   // The profile this object was initialized with.
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(ThemeSource);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_THEME_SOURCE_H_