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

mojo/public/c/tests/system/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 wait API (the functions declared in
 // mojo/public/c/include/mojo/system/wait.h).
 
 #include <mojo/system/wait.h>
 
 #include <mojo/result.h>
 #include <mojo/system/handle.h>
 
-#include "testing/gtest/include/gtest/gtest.h"
+#include "gtest/gtest.h"
 
 namespace {
 
 TEST(WaitTest, InvalidHandle) {
   EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
             MojoWait(MOJO_HANDLE_INVALID, ~MOJO_HANDLE_SIGNAL_NONE, 1000000u,
                      nullptr));
 
   const MojoHandle h = MOJO_HANDLE_INVALID;
   MojoHandleSignals sig = ~MOJO_HANDLE_SIGNAL_NONE;
@@ skipping 13 matching lines @@
   uint32_t result_index = static_cast<uint32_t>(-1);
   EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED,
             MojoWaitMany(nullptr, nullptr, 0u, static_cast<MojoDeadline>(1000),
                          &result_index, nullptr));
   EXPECT_EQ(static_cast<uint32_t>(-1), result_index);
 }
 
 // TODO(vtl): Write tests that actually test waiting.
 
 }  // namespace