Cope gracefully with scripts querying stats before client has started.

remoting/client/plugin/chromoting_instance.cc

 // Copyright (c) 2011 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.
 
 #include "remoting/client/plugin/chromoting_instance.h"
 
 #include <string>
 #include <vector>
 
 #include "base/message_loop.h"
@@ skipping 273 matching lines @@
     object->Init();
 
     // The pp::Var takes ownership of object here.
     instance_object_ = pp::Var(this, object);
   }
 
   return instance_object_;
 }
 
 ChromotingStats* ChromotingInstance::GetStats() {
+  if (!client_.get())
+    return NULL;
   return client_->GetStats();
 }
 
 }  // namespace remoting