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

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

Index: mojo/public/cpp/bindings/tests/message_builder_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/message_builder_unittest.cc b/mojo/public/cpp/bindings/tests/message_builder_unittest.cc
index 19202bafaacf9547dfda8b67c64159426b2e7426..14c090201260f65ba63f5f50fc290f40664d66da 100644
--- a/mojo/public/cpp/bindings/tests/message_builder_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/message_builder_unittest.cc
@@ -2,10 +2,10 @@
 // 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 {