reduce goma_jobs to 50 on windows
reduce goma_jobs to 50 on windows

Use chromium_utils.IsWindows() instead of sys.platform == 'win32'
Review URL: https://chromiumcodereview.appspot.com/10834156

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@149905 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build