DevTools: introduce emulation-enabled-on-load test.

BUG=335790

Review URL: https://codereview.chromium.org/163243004

git-svn-id: svn://svn.chromium.org/blink/trunk@167334 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove sync-repeated-and-caching test expectation.

Test no longer flaky on Windows, remove expectation.

R=jochen@chromium.org
BUG=327877

Review URL: https://codereview.chromium.org/170393003

git-svn-id: svn://svn.chromium.org/blink/trunk@167335 bbb929c8-8fbe-4397-9dbb-9b2b20218538