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

chrome/browser/sync/sessions/session_state.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.
 
 // The 'sessions' namespace comprises all the pieces of state that are
 // combined to form a SyncSession instance. In that way, it can be thought of
 // as an extension of the SyncSession type itself. Session scoping gives
 // context to things like "conflict progress", "update progress", etc, and the
 // separation this file provides allows clients to only include the parts they
 // need rather than the entire session stack.
@@ skipping 14 matching lines @@
 #include "chrome/browser/sync/sessions/ordered_commit_set.h"
 #include "chrome/browser/sync/protocol/sync_protocol_error.h"
 #include "chrome/browser/sync/syncable/model_type.h"
 #include "chrome/browser/sync/syncable/model_type_payload_map.h"
 #include "chrome/browser/sync/syncable/syncable.h"
 
 namespace base {
 class DictionaryValue;
 }
 
-namespace syncable {
-class DirectoryManager;
-}
-
 namespace browser_sync {
 namespace sessions {
 
 class UpdateProgress;
 
 // A container for the source of a sync session. This includes the update
 // source, the datatypes triggering the sync session, and possible session
 // specific payloads which should be sent to the server.
 struct SyncSourceInfo {
   SyncSourceInfo();
@@ skipping 292 matching lines @@
   ~PerModelSafeGroupState();
 
   UpdateProgress update_progress;
   ConflictProgress conflict_progress;
 };
 
 }  // namespace sessions
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_SESSIONS_SESSION_STATE_H_