Use a direct include of the message_loop header in net/, part 1.

net/base/file_stream_context.h

 // Copyright (c) 2012 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.
 
 // This file defines FileStream::Context class.
 // The general design of FileStream is as follows: file_stream.h defines
 // FileStream class which basically is just an "wrapper" not containing any
 // specific implementation details. It re-routes all its method calls to
 // the instance of FileStream::Context (FileStream holds a scoped_ptr to
 // FileStream::Context instance). Context was extracted into a different class
 // to be able to do and finish all async operations even when FileStream
 // instance is deleted. So FileStream's destructor can schedule file
 // closing to be done by Context in WorkerPool (or the TaskRunner passed to
 // constructor) and then just return (releasing Context pointer from
 // scoped_ptr) without waiting for actual closing to complete.
 // Implementation of FileStream::Context is divided in two parts: some methods
 // and members are platform-independent and some depend on the platform. This
 // header file contains the complete definition of Context class including all
 // platform-dependent parts (because of that it has a lot of #if-#else
 // branching). Implementations of all platform-independent methods are
 // located in file_stream_context.cc, and all platform-dependent methods are
 // in file_stream_context_{win,posix}.cc. This separation provides better
 // readability of Context's code. And we tried to make as much Context code
 // platform-independent as possible. So file_stream_context_{win,posix}.cc are
 // much smaller than file_stream_context.cc now.
 
 #ifndef NET_BASE_FILE_STREAM_CONTEXT_H_
 #define NET_BASE_FILE_STREAM_CONTEXT_H_
 
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/platform_file.h"
 #include "base/task_runner.h"
 #include "net/base/completion_callback.h"
 #include "net/base/file_stream.h"
 #include "net/base/file_stream_metrics.h"
 #include "net/base/file_stream_whence.h"
 #include "net/base/net_log.h"
 
 #if defined(OS_POSIX)
 #include <errno.h>
@@ skipping 182 matching lines @@
   FileErrorSource error_source_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_FILE_STREAM_CONTEXT_H_