Mandoline: ConnectToApplication and ConnectToService should fail gracefully

mojo/application/public/cpp/application_impl.h

 // Copyright 2014 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_APPLICATION_PUBLIC_CPP_APPLICATION_IMPL_H_
 #define MOJO_APPLICATION_PUBLIC_CPP_APPLICATION_IMPL_H_
 
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 74 matching lines @@
   ApplicationConnection* ConnectToApplication(mojo::URLRequestPtr request);
 
   // Closes the |connection|.
   void CloseConnection(ApplicationConnection* connection);
 
   // Connect to application identified by |request->url| and connect to the
   // service implementation of the interface identified by |Interface|.
   template <typename Interface>
   void ConnectToService(mojo::URLRequestPtr request,
                         InterfacePtr<Interface>* ptr) {
-    ConnectToApplication(request.Pass())->ConnectToService(ptr);
+    ApplicationConnection* connection = ConnectToApplication(request.Pass());
+    if (!connection)
+      return;
+    connection->ConnectToService(ptr);
   }
 
   // Application implementation.
   void Initialize(ShellPtr shell, const mojo::String& url) override;
 
   // Block until the Application is initialized, if it is not already.
   void WaitForInitialize();
 
   // Unbinds the Shell and Application connections. Can be used to re-bind the
   // handles to another implementation of ApplicationImpl, for instance when
@@ skipping 34 matching lines @@
   bool quit_requested_;
   bool in_destructor_;
   base::WeakPtrFactory<ApplicationImpl> weak_factory_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(ApplicationImpl);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_APPLICATION_PUBLIC_CPP_APPLICATION_IMPL_H_