Mojo: Use the MessagePipe creation helper whenever possible/reasonable in tests.

mojo/public/cpp/bindings/tests/handle_passing_unittest.cc

 // Copyright 2013 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 "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 #include "mojo/public/interfaces/bindings/tests/sample_factory.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 158 matching lines @@
 
 TEST_F(HandlePassingTest, Basic) {
   sample::FactoryPtr factory;
   BindToProxy(new SampleFactoryImpl(), &factory);
 
   SampleFactoryClientImpl factory_client;
   factory_client.set_expected_text_reply(kText1);
 
   factory.set_client(&factory_client);
 
-  ScopedMessagePipeHandle pipe0, pipe1;
-  CreateMessagePipe(&pipe0, &pipe1);
+  MessagePipe pipe0;
+  EXPECT_TRUE(WriteTextMessage(pipe0.handle1.get(), kText1));
 
-  EXPECT_TRUE(WriteTextMessage(pipe1.get(), kText1));
-
-  ScopedMessagePipeHandle pipe2, pipe3;
-  CreateMessagePipe(&pipe2, &pipe3);
-
-  EXPECT_TRUE(WriteTextMessage(pipe3.get(), kText2));
+  MessagePipe pipe1;
+  EXPECT_TRUE(WriteTextMessage(pipe1.handle1.get(), kText2));
 
   sample::RequestPtr request(sample::Request::New());
   request->x = 1;
-  request->pipe = pipe2.Pass();
-  factory->DoStuff(request.Pass(), pipe0.Pass());
+  request->pipe = pipe1.handle0.Pass();
+  factory->DoStuff(request.Pass(), pipe0.handle0.Pass());
 
   EXPECT_FALSE(factory_client.got_response());
 
   PumpMessages();
 
   EXPECT_TRUE(factory_client.got_response());
 }
 
 TEST_F(HandlePassingTest, PassInvalid) {
   sample::FactoryPtr factory;
@@ skipping 119 matching lines @@
 
   PumpMessages();  // Yield for results.
 
   EXPECT_EQ(std::string("object1"), name1);
   EXPECT_EQ(std::string("object2"), name2);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo