Cleanup: Remove unneeded forward declarations in base, dbug, gpu, ipc, jingle, and media.

dbus/object_proxy.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 DBUS_OBJECT_PROXY_H_
 #define DBUS_OBJECT_PROXY_H_
 #pragma once
 
+#include <dbus/dbus.h>
+
 #include <map>
 #include <string>
 #include <vector>
-#include <dbus/dbus.h>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/time.h"
 
-class MessageLoop;
-
 namespace dbus {
 
 class Bus;
 class MethodCall;
 class Response;
 class Signal;
 
 // ObjectProxy is used to communicate with remote objects, mainly for
 // calling methods of these objects.
 //
@@ skipping 158 matching lines @@
   MethodTable method_table_;
 
   std::vector<std::string> match_rules_;
 
   DISALLOW_COPY_AND_ASSIGN(ObjectProxy);
 };
 
 }  // namespace dbus
 
 #endif  // DBUS_OBJECT_PROXY_H_