Improve testing with File() keyword, found a few bugs along the way

TEST=new smoke tests

Review URL: http://codereview.chromium.org/2865039

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@51824 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed