Enable WebGL DebugRenderInfo extensions for all users

This does not remove the now-unnecessary finch experiment framework. That will come in a later CL.

BUG=335373
R=kbr@chromium.org

Review URL: https://codereview.chromium.org/134233007

git-svn-id: svn://svn.chromium.org/blink/trunk@165273 bbb929c8-8fbe-4397-9dbb-9b2b20218538