I discovered this because animation frames weren't being executed since the
test config wasn't properly replicated in the test_runner for secondary renderer.

Previously in the old test harness, this worked because DevTools was the
secondary window and LayoutTestDevToolsBindings observes the DevTools window and
implements RenderFrameCreated.

This includes a test that we previously couldn't migrate because rAF was never called.

Bug: 667560
Change-Id: I286f27af3e4b87ffff368f2284a9a3b373e9b269
Reviewed-on: https://chromium-review.googlesource.com/764853


Commit-Queue: Will Chen <chenwilliam@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516087}