Add chrome perf tests and sniffer to GN build.

ppapi/BUILD.gn

 # 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.
 
 gypi_values = exec_script(
     "//build/gypi_to_gn.py",
     [ rebase_path("ppapi_sources.gypi") ],
     "scope",
     [ "ppapi_sources.gypi" ])
 
@@ skipping 174 matching lines @@
     "shared_impl/resource_tracker.cc",
     "shared_impl/resource_tracker.h",
     "shared_impl/resource_var.cc",
     "shared_impl/resource_var.h",
     "shared_impl/scoped_pp_resource.cc",
     "shared_impl/scoped_pp_resource.h",
     "shared_impl/scoped_pp_var.cc",
     "shared_impl/scoped_pp_var.h",
     "shared_impl/socket_option_data.cc",
     "shared_impl/socket_option_data.h",
+    "shared_impl/test_harness_utils.cc",
+    "shared_impl/test_harness_utils.h",
     "shared_impl/thread_aware_callback.cc",
     "shared_impl/thread_aware_callback.h",
     "shared_impl/time_conversion.cc",
     "shared_impl/time_conversion.h",
     "shared_impl/tracked_callback.cc",
     "shared_impl/tracked_callback.h",
     "shared_impl/url_request_info_data.cc",
     "shared_impl/url_request_info_data.h",
     "shared_impl/url_response_info_data.cc",
     "shared_impl/url_response_info_data.h",
@@ skipping 604 matching lines @@
     ":ppapi_shared",
     "//base/test:test_support",
     "//ipc",
     "//ipc:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
 # TODO(GYP) other targets from ppapi_tests.gyp