DRT requires that we get animation started notifications for the animation tests to succeed. If we enable compositor animations, then this will not happen; the ticking of animations is tied to the commits, which don't happen regularly in DRT like they do in chrome. To compensate, the single thread proxy will force a single composite upon getting notified of a new animation. This should only happen for DRT and therefore needs to be enabled via a setting.
Created attachment 155955 [details] Patch
Please wait for approval from abarth@webkit.org, dglazkov@chromium.org, fishd@chromium.org, jamesr@chromium.org or tkent@chromium.org before submitting, as this patch contains changes to the Chromium public API. See also https://trac.webkit.org/wiki/ChromiumWebKitAPI.
Marked LayoutTest bugs, bugs with Chromium IDs, and some others as WontFix. Test failure bugs still are trackable via TestExpectations or disabled unit tests.