[webapi] Automate 3 tests for HTML5 SVG as reftest.

Fail Reason:[XWALK-2735]

Impacted TCs num: New 0, Update 3, Delete 0
Unit test Platform: Andriod
Unit test result summary: Pass 0, Fail 3, Blocked 0
Why not refine the test case to avoid such border? This test cares only about `<svg>` inside `<label>`

You can submit the refined test and reference to W3C too.