Adding stats-gathering hook to determine if we fast-scroll on the main thread.
Created attachment 166501 [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.
Comment on attachment 166501 [details] Patch Patch seems driven by Chromium needs. Clearing review flag for now.