Fix keyboard_unittests

BUG=331690
R=penghuang@chromium.org

Review URL: https://codereview.chromium.org/136033005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244919 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244919