GN: Fix Mac build for some tests.

tools/gn/secondary/testing/gtest/BUILD.gn

 # Copyright (c) 2013 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.
 
 config("gtest_config") {
   defines = [
     "UNIT_TEST",
 
     # In order to allow regex matches in gtest to be shared between Windows
     # and other systems, we tell gtest to always use it's internal engine.
@@ skipping 53 matching lines @@
     "src/gtest-test-part.cc",
     "src/gtest-typed-test.cc",
     "src/gtest.cc",
     "../multiprocess_func_list.cc",
     "../multiprocess_func_list.h",
     "../platform_test.h",
   ]
 
   if (is_mac) {
     sources += [
-      "gtest_mac.h",
-      "gtest_mac.mm",
-      "platform_test_mac.mm",
+      "../gtest_mac.h",
+      "../gtest_mac.mm",
+      "../platform_test_mac.mm",
     ]
   }
 
   include_dirs = [ "." ]
 
   all_dependent_configs = [ ":gtest_config" ]
 
   configs -= "//build/config/compiler:chromium_code"
   configs += "//build/config/compiler:no_chromium_code"
 }