components: Cleanup class/struct fwd declarations

components/webdata/common/web_database_backend.h

 // Copyright 2013 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_WEBDATA_COMMON_WEB_DATABASE_BACKEND_H_
 #define COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_BACKEND_H_
 
 #include <memory>
 
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/ref_counted_delete_on_message_loop.h"
 #include "base/memory/scoped_vector.h"
 #include "base/single_thread_task_runner.h"
 #include "components/webdata/common/web_database_service.h"
 #include "components/webdata/common/webdata_export.h"
 
 class WebDatabase;
 class WebDatabaseTable;
 class WebDataRequest;
 class WebDataRequestManager;
 
-namespace tracked_objects {
-class Location;
-}
-
 // WebDatabaseBackend handles all database tasks posted by
 // WebDatabaseService. It is refcounted to allow asynchronous destruction on the
 // DB thread.
 
 class WEBDATA_EXPORT WebDatabaseBackend
     : public base::RefCountedDeleteOnMessageLoop<WebDatabaseBackend> {
  public:
   class Delegate {
    public:
     virtual ~Delegate() {}
@@ skipping 93 matching lines @@
   // diagnostic information.
   std::string diagnostics_;
 
   // Delegate. See the class definition above for more information.
   std::unique_ptr<Delegate> delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(WebDatabaseBackend);
 };
 
 #endif  // COMPONENTS_WEBDATA_COMMON_WEB_DATABASE_BACKEND_H_