Remove obviously unneeded forward declarations from headers under src/{app,base,net}.

app/surface/transport_dib.h

 // Copyright (c) 2010 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 APP_SURFACE_TRANSPORT_DIB_H_
 #define APP_SURFACE_TRANSPORT_DIB_H_
 #pragma once
 
 #include "base/basictypes.h"
 
 #if defined(OS_WIN) || defined(OS_MACOSX)
 #include "base/shared_memory.h"
 #endif
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(USE_X11)
 #include "app/x11_util.h"
 #endif
 
-namespace gfx {
-class Size;
-}
 namespace skia {
 class PlatformCanvas;
 }
 
 // -----------------------------------------------------------------------------
 // A TransportDIB is a block of memory that is used to transport pixels
 // between processes: from the renderer process to the browser, and
 // between renderer and plugin processes.
 // -----------------------------------------------------------------------------
 class TransportDIB {
@@ skipping 136 matching lines @@
   int key_;  // SysV shared memory id
   void* address_;  // mapped address
   XSharedMemoryId x_shm_;  // X id for the shared segment
   Display* display_;  // connection to the X server
 #endif
   size_t size_;  // length, in bytes
 
   DISALLOW_COPY_AND_ASSIGN(TransportDIB);
 };
 
-class MessageLoop;
-
 #endif  // APP_SURFACE_TRANSPORT_DIB_H_