Move everything inside a polymer element so the styling scoping works cross browser.

Without this change the content didn't get any styling in FireFox.

BUG=skia:

Review URL: https://codereview.chromium.org/831803003
This adds bulk triage with one click and refactors some code so we can re-use it across views.

The next CL will complete the integration into the high level triage view. Then we'll be able to triage across tests with a single click.

BUG=skia:2930

Review URL: https://codereview.chromium.org/806083003