Moves some files into mojo/common

mojo/common/scoped_message_pipe.cc

 // 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.
 
-#include "mojo/shell/scoped_message_pipe.h"
+#include "mojo/common/scoped_message_pipe.h"
 
 namespace mojo {
-namespace shell {
+namespace common {
 
 ScopedMessagePipe::ScopedMessagePipe()
     : handle_0_(MOJO_HANDLE_INVALID),
       handle_1_(MOJO_HANDLE_INVALID) {
   MojoCreateMessagePipe(&handle_0_, &handle_1_);
 }
 
 ScopedMessagePipe::~ScopedMessagePipe() {
   if (handle_0_ != MOJO_HANDLE_INVALID)
     MojoClose(handle_0_);
 
   if (handle_1_ != MOJO_HANDLE_INVALID)
     MojoClose(handle_1_);
 }
 
-}  // namespace shell
+}  // namespace common
 }  // namespace mojo