mojo/public: Include gtest.h as "gtest/gtest.h", instead of via "absolute" path.

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

 // Copyright 2015 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 "gtest/gtest.h"
 #include "mojo/public/cpp/bindings/lib/bindings_serialization.h"
 #include "mojo/public/cpp/bindings/lib/message_builder.h"
 #include "mojo/public/cpp/bindings/lib/message_internal.h"
-#include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace test {
 namespace {
 
 TEST(MessageBuilderTest, MessageBuilder) {
   char payload[41];
   MessageBuilder b(123u, sizeof(payload));
 
   // The payload size should be a multiple of 8.
@@ skipping 48 matching lines @@
   EXPECT_EQ(123u, msg_hdr->name);
   EXPECT_EQ(internal::kMessageIsResponse, msg_hdr->flags);
   EXPECT_EQ(1u, msg_hdr->version);
   EXPECT_EQ(0ul, msg_hdr->request_id);
   EXPECT_EQ(sizeof(internal::MessageHeaderWithRequestID), msg_hdr->num_bytes);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo