GitLab

This CL should facilitate conversion of cr- elements and help debugging
them in isolation.

To view elements in demo_elements.html, navigate to:
chrome://resources/cr_elements/v0_8/demo_page.html

BUG=485381

Review URL: https://codereview.chromium.org/1124073007

Cr-Commit-Position: refs/heads/master@{#330297}