chrome: Cleanup class/struct forward declarations

chrome/browser/android/thumbnail/thumbnail_cache.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 CHROME_BROWSER_ANDROID_THUMBNAIL_THUMBNAIL_CACHE_H_
 #define CHROME_BROWSER_ANDROID_THUMBNAIL_THUMBNAIL_CACHE_H_
 
 #include <stddef.h>
 
 #include <list>
@@ skipping 12 matching lines @@
 #include "chrome/browser/android/thumbnail/thumbnail.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 #include "ui/android/resources/ui_resource_provider.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/geometry/size_f.h"
 #include "url/gurl.h"
 
 namespace base {
-class File;
 class Time;
 }
 
-namespace content {
-class ContentViewCore;
-}
-
 typedef std::list<TabId> TabIdList;
 
 class ThumbnailCacheObserver {
  public:
   virtual void OnFinishedThumbnailRead(TabId tab_id) = 0;
 };
 
 class ThumbnailCache : ThumbnailDelegate {
  public:
   ThumbnailCache(size_t default_cache_size,
@@ skipping 117 matching lines @@
 
   ui::UIResourceProvider* ui_resource_provider_;
 
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_;
   base::WeakPtrFactory<ThumbnailCache> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ThumbnailCache);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_THUMBNAIL_THUMBNAIL_CACHE_H_