Chromium does not set m_directionInvertedFromDevice on PlatformWheelEvent instances when constructing them and so leaves the webkitDirectionInvertedFromDevice property always set to false. Plumb this property through the Chromium WebKit layer.
Created attachment 181038 [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 181038 [details] Patch This CL is incomplete and needs some more work.