Use the mojo::shell namespace consistently underly shell/.

shell/context.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 SHELL_CONTEXT_H_
 #define SHELL_CONTEXT_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "mojo/edk/embedder/process_delegate.h"
 #include "shell/application_manager/application_manager.h"
 #include "shell/task_runners.h"
 #include "shell/url_resolver.h"
 
 namespace mojo {
-
 namespace shell {
 
 class ExternalApplicationListener;
 class NativeApplicationLoader;
 
 // The "global" context for the shell's main process.
 class Context : public ApplicationManager::Delegate,
                 public embedder::ProcessDelegate {
  public:
   Context();
@@ skipping 55 matching lines @@
   GURL shell_file_root_;
   GURL command_line_cwd_;
 
   DISALLOW_COPY_AND_ASSIGN(Context);
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // SHELL_CONTEXT_H_