Sync web-platform-tests PR 14652 into mozilla-central (this bug is closed when the sync is complete). PR: https://github.com/web-platform-tests/wpt/pull/14652 Details from upstream follow. Andrew Comminos <acomminos@fb.com> wrote: > Perform flexbox child hit testing by testing all children atomically > > When two child elements of a flexbox overlap (for example, due to > negative margins), the element drawn in the foreground may not actually > capture the hit if the element underneath it is hit-tested in an earlier > phase (e.g. foreground before child block background), despite being > occluded. This is because painting of flexbox children is done > atomically (all phases at once). This change makes hit testing atomic as > well, in accordance with the spec [1]. > > [1] https://www.w3.org/TR/css-flexbox-1/#painting > > Bug: 844505 > Change-Id: Iceab80b42f19488dcb59565ea3c0ce40d48c483b > > Reviewed-on: https://chromium-review.googlesource.com/1388206 > WPT-Export-Revision: 2eed18d128f0e1a535471df2a785fc13bdb7702e

Pushed to try https://treeherder.mozilla.org/#/jobs?repo=try&revision=09266578bce9bebe8ca2135ef612a4affb0e7227

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=e866edbcf78438d533834b827f17c59dd4495f13

Pushed to try https://treeherder.mozilla.org/#/jobs?repo=try&revision=80628a75bc727bf734bcf64aec56dc59052a616d

Failed to get results from try push

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=0942e03a584ab7f8b72f5ad6bdf824bb6b98b11e

Pushed by james@hoppipolla.co.uk: https://hg.mozilla.org/integration/mozilla-inbound/rev/c49c447610ee [wpt PR 14652] - Perform flexbox child hit testing by testing all children atomically, a=testonly

Pushed by james@hoppipolla.co.uk: https://hg.mozilla.org/integration/mozilla-inbound/rev/37083c63895a [wpt PR 14652] - Perform flexbox child hit testing by testing all children atomically, a=testonly