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

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

 // 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.
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
 
+#include "gtest/gtest.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "mojo/public/interfaces/bindings/tests/sample_service.mojom.h"
-#include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 
 template <>
 struct TypeConverter<int32_t, sample::BarPtr> {
   static int32_t Convert(const sample::BarPtr& bar) {
     return static_cast<int32_t>(bar->alpha) << 16 |
            static_cast<int32_t>(bar->beta) << 8 |
            static_cast<int32_t>(bar->gamma);
   }
@@ skipping 340 matching lines @@
   ASSERT_FALSE(defaults->a22.is_null());
   EXPECT_EQ(imported::Shape::RECTANGLE, defaults->a22->shape);
   EXPECT_EQ(imported::Color::BLACK, defaults->a22->color);
   EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, defaults->a23);
   EXPECT_EQ(0x123456789, defaults->a24);
   EXPECT_EQ(-0x123456789, defaults->a25);
 }
 
 }  // namespace
 }  // namespace sample