Revise comments on various Shell interfaces. Make some methods private on ShellConnection.

mojo/shell/public/cpp/app_lifetime_helper.h

 // Copyright 2015 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 MOJO_SHELL_PUBLIC_CPP_APP_LIFETIME_HELPER_H_
 #define MOJO_SHELL_PUBLIC_CPP_APP_LIFETIME_HELPER_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/single_thread_task_runner.h"
 
 namespace mojo {
 
+class Shell;
 class ShellConnection;
 class AppLifetimeHelper;
 
 // A service implementation should keep this object as a member variable to hold
 // a reference on the application.
 // Since services can live on different threads than the app, this class is
 // safe to use on any thread. However, each instance should only be used on one
 // thread at a time (otherwise there'll be races between the addref resulting
 // from cloning and destruction).
 class AppRefCount {
@@ skipping 26 matching lines @@
 
 // This is a helper class for apps to manage their lifetime, specifically so
 // apps can quit when they're not used anymore.
 // An app can contain an object of this class as a member variable. Each time it
 // creates an instance of a service, it gives it a refcount using
 // CreateAppRefCount. The service implementation then keeps that object as a
 // member variable. When all the service implemenations go away, the app will be
 // quit with a call to mojo::ShellConnection::Terminate().
 class AppLifetimeHelper {
  public:
-  explicit AppLifetimeHelper(ShellConnection* app);
+  explicit AppLifetimeHelper(Shell* shell);
   ~AppLifetimeHelper();
 
   scoped_ptr<AppRefCount> CreateAppRefCount();
 
  private:
   friend AppRefCount;
   void AddRef();
   void Release();
 
   friend ShellConnection;
   void OnQuit();
 
-  ShellConnection* app_;
+  Shell* shell_;
   int ref_count_;
 
   DISALLOW_COPY_AND_ASSIGN(AppLifetimeHelper);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_PUBLIC_CPP_APP_LIFETIME_HELPER_H_