Make first TouchStart and first TouchMove events on a flinging layer non-blocking.
Blocking touchstart and first touchMove handlers during fling can cause major hiccups during
fling boosting / flywheel fling.
We are doing a passive event listener during fling intervention experiment to see if we can
improve the fling performance by forcing touchstart and first touchmove to be passive when
there is an active fling animation.
BUG=595327
Review-Url: https://codereview.chromium.org/2233543002
Cr-Commit-Position: refs/heads/master@{#413189}
18 files changed
