Replace hasAttribute with the check for actual value

This change replaces the use of hasAttribute() by a
better and correct approach, to check if the actual
value is greater than or equal to zero. This patch also
includes a Ref Test which demonstrates the setting of attribute
within a 'use' tag to test the changed code path.

BUG=235256
R=pdr@chromium.org

Review URL: https://chromiumcodereview.appspot.com/17287012

git-svn-id: svn://svn.chromium.org/blink/trunk@152911 bbb929c8-8fbe-4397-9dbb-9b2b20218538
3 files changed