Make sure that Content Handled application can be connected multiple times.

mojo/application_manager/background_shell_application_loader.h

Index: mojo/application_manager/background_shell_application_loader.h
diff --git a/mojo/application_manager/background_shell_application_loader.h b/mojo/application_manager/background_shell_application_loader.h
index 399df434ea648059687cb9704365499433155689..284ecd1b677fcb9229bb8ecf12a84c9049e40fb7 100644
--- a/mojo/application_manager/background_shell_application_loader.h
+++ b/mojo/application_manager/background_shell_application_loader.h
@@ -29,13 +29,12 @@ class MOJO_APPLICATION_MANAGER_EXPORT BackgroundShellApplicationLoader
   // ApplicationLoader overrides:
   void Load(ApplicationManager* manager,
             const GURL& url,
-            scoped_refptr<LoadCallbacks> callbacks) override;
+            ScopedMessagePipeHandle shell_handle,
+            LoadCallback callbacks) override;
   void OnApplicationError(ApplicationManager* manager,
                           const GURL& url) override;
 
  private:
-  class BackgroundLoader;
-
   // |base::DelegateSimpleThread::Delegate| method:
   void Run() override;
 
@@ -45,7 +44,7 @@ class MOJO_APPLICATION_MANAGER_EXPORT BackgroundShellApplicationLoader
   // isn't thread safe).
   void LoadOnBackgroundThread(ApplicationManager* manager,
                               const GURL& url,
-                              ScopedMessagePipeHandle* shell_handle);
+                              ScopedMessagePipeHandle shell_handle);
   void OnApplicationErrorOnBackgroundThread(ApplicationManager* manager,
                                             const GURL& url);
   bool quit_on_shutdown_;
@@ -66,9 +65,6 @@ class MOJO_APPLICATION_MANAGER_EXPORT BackgroundShellApplicationLoader
 
   scoped_ptr<base::DelegateSimpleThread> thread_;
 
-  // Lives on |thread_|. Trivial interface that calls through to |loader_|.
-  BackgroundLoader* background_loader_;
-
   DISALLOW_COPY_AND_ASSIGN(BackgroundShellApplicationLoader);
 };