components: Cleanup class/struct fwd declarations

components/drive/chromeos/file_system.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 COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_H_
 #define COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 18 matching lines @@
 }  // namespace base
 
 namespace google_apis {
 class AboutResource;
 class ResourceEntry;
 }  // namespace google_apis
 
 namespace drive {
 struct ClientContext;
 class EventLogger;
-class FileCacheEntry;
 class FileSystemObserver;
 class JobScheduler;
 
 namespace internal {
 class AboutResourceLoader;
 class ChangeListLoader;
 class DirectoryLoader;
 class FileCache;
 class LoaderController;
 class ResourceMetadata;
@@ skipping 258 matching lines @@
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<FileSystem> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSystem);
 };
 
 }  // namespace drive
 
 #endif  // COMPONENTS_DRIVE_CHROMEOS_FILE_SYSTEM_H_