chromecast: Cleanup class/struct fwd declarations

chromecast/browser/android/cast_window_android.h

 // Copyright 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 CHROMECAST_BROWSER_ANDROID_CAST_WINDOW_ANDROID_H_
 #define CHROMECAST_BROWSER_ANDROID_CAST_WINDOW_ANDROID_H_
 
 #include <jni.h>
 #include <stdint.h>
 
@@ skipping 11 matching lines @@
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/content_switches.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/native_widget_types.h"
 
 class GURL;
 
 namespace content {
 class BrowserContext;
-class SiteInstance;
 class WebContents;
 }  // namespace content
 
 namespace chromecast {
 namespace shell {
 class CastContentWindow;
 
 class CastWindowAndroid : public content::WebContentsDelegate,
                           public content::WebContentsObserver {
  public:
@@ skipping 43 matching lines @@
 
   base::WeakPtrFactory<CastWindowAndroid> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CastWindowAndroid);
 };
 
 }  // namespace shell
 }  // namespace chromecast
 
 #endif  // CHROMECAST_BROWSER_ANDROID_CAST_WINDOW_ANDROID_H_