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

mojo/public/cpp/system/tests/wait_unittest.cc

 // Copyright 2016 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.
 
 // This file tests the C++ wrappers in mojo/public/cpp/system/wait.h.
 
 #include "mojo/public/cpp/system/wait.h"
 
 #include <vector>
 
+#include "gtest/gtest.h"
 #include "mojo/public/cpp/system/handle.h"
 #include "mojo/public/cpp/system/message_pipe.h"
-#include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace {
 
 TEST(WaitTest, InvalidArgs) {
   ScopedHandle h;
 
   EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
             Wait(h.get(), ~MOJO_HANDLE_SIGNAL_NONE, 1000000, nullptr));
 
@@ skipping 68 matching lines @@
     WaitManyResult wmr(MOJO_RESULT_FAILED_PRECONDITION, 5u);
     EXPECT_TRUE(wmr.IsIndexValid());
     EXPECT_TRUE(wmr.AreSignalsStatesValid());
     EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, wmr.result);
     EXPECT_EQ(5u, wmr.index);
   }
 }
 
 }  // namespace
 }  // namespace mojo