PPAPI: Make TestMessageHandler.Exceptions work

ppapi/tests/test_message_handler.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 PPAPI_TESTS_TEST_MESSAGE_HANDLER_H_
 #define PPAPI_TESTS_TEST_MESSAGE_HANDLER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 10 matching lines @@
  private:
   // TestCase implementation.
   virtual bool Init();
   virtual void RunTests(const std::string& filter);
   virtual void HandleMessage(const pp::Var& message_data);
 
   std::string TestRegisterErrorConditions();
   std::string TestPostMessageAndAwaitResponse();
   std::string TestExceptions();
 
+  // Wait for HandleMessage to be called, and return the Var it received.
+  pp::Var WaitForMessage();
+  NestedEvent message_received_;
+  pp::Var last_message_;
+
   const PPB_Messaging_1_2* ppb_messaging_if_;
   pp::SimpleThread handler_thread_;
 
-  // For TestExceptions():
-  NestedEvent message_received_;
-  std::string last_message_;
 };
 
 #endif  // PPAPI_TESTS_TEST_MESSAGE_HANDLER_H_