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

mojo/shell/dynamic_application_loader.h

Index: mojo/shell/dynamic_application_loader.h
diff --git a/mojo/shell/dynamic_application_loader.h b/mojo/shell/dynamic_application_loader.h
index 5644100000bc9e1137ae93ca62a3aa634a58641d..7a7b41b5f603de763c997eb37df51aab798406b3 100644
--- a/mojo/shell/dynamic_application_loader.h
+++ b/mojo/shell/dynamic_application_loader.h
@@ -40,7 +40,8 @@ class DynamicApplicationLoader : public ApplicationLoader {
   // ApplicationLoader methods:
   void Load(ApplicationManager* manager,
             const GURL& url,
-            scoped_refptr<LoadCallbacks> callbacks) override;
+            ScopedMessagePipeHandle shell_handle,
+            LoadCallback callback) override;
   void OnApplicationError(ApplicationManager* manager,
                           const GURL& url) override;