Build gtest from source rather than using SDK-provided version

build_tools/test_build_tools.py

 # Copyright 2014 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import mock
 from mock import Mock, patch
 import StringIO
 import unittest
 
 import webports
@@ skipping 100 matching lines @@
 
    def test_deps(self):
      self.assertEqual(
          find_effected_packages(['ports/hello', 'ports/ruby'], False, None),
          ['hello', 'ruby', 'ruby-ppapi'])
 
      # The common dependencies of vim and nano should only appear once in this
      # list.
      self.assertEqual(
          find_effected_packages(['ports/hello', 'ports/ruby'], True, None),
-         ['hello', 'corelibs', 'glibc-compat', 'ncurses', 'readline', 'zlib',
-          'ruby', 'libtar', 'nacl-spawn', 'ruby-ppapi'])
+         ['hello', 'corelibs', 'gtest', 'glibc-compat', 'ncurses', 'readline',
+          'zlib', 'ruby', 'libtar', 'nacl-spawn', 'ruby-ppapi'])
 
    def test_filter(self):
      effected = find_effected_packages(['ports/corelibs'], True,
          ['corelibs', 'glibc-compat'])
      self.assertEqual(effected, ['corelibs', 'glibc-compat'])