Cleanup: Remove unneeded forward declarations in chrome/browser/sync.

chrome/browser/sync/engine/syncer.h

 // Copyright (c) 2011 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_SYNC_ENGINE_SYNCER_H_
 #define CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_
 #pragma once
 
 #include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/sync/engine/conflict_resolver.h"
 #include "chrome/browser/sync/engine/syncer_types.h"
 #include "chrome/browser/sync/engine/syncproto.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/syncable/directory_event.h"
 #include "chrome/browser/sync/syncable/model_type.h"
 #include "chrome/browser/sync/util/extensions_activity_monitor.h"
 
 namespace syncable {
-class Directory;
-class DirectoryManager;
 class Entry;
-class Id;
 class MutableEntry;
-class WriteTransaction;
 }  // namespace syncable
 
 namespace browser_sync {
 
-class ModelSafeWorker;
-class ServerConnectionManager;
-class SyncProcessState;
-class URLFactory;
-struct HttpResponse;
-
 enum SyncerStep {
   SYNCER_BEGIN,
   CLEANUP_DISABLED_TYPES,
   DOWNLOAD_UPDATES,
   PROCESS_CLIENT_COMMAND,
   VERIFY_UPDATES,
   PROCESS_UPDATES,
   STORE_TIMESTAMPS,
   APPLY_UPDATES,
   BUILD_COMMIT_REQUEST,
@@ skipping 83 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(Syncer);
 };
 
 // Utility function declarations.
 void CopyServerFields(syncable::Entry* src, syncable::MutableEntry* dest);
 void ClearServerData(syncable::MutableEntry* entry);
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_