Combine settings about compositing scrollable frames (followup)

Cleanup after cross-repository changes
https://codereview.chromium.org/239533002 and
https://codereview.chromium.org/239463003

BUG=304900
TBR=abarth@chromium.org

Review URL: https://codereview.chromium.org/240353005

git-svn-id: svn://svn.chromium.org/blink/trunk@171808 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark virtual/threaded/animations/interpolation/webkit-transform-interpolation.html as flaky

BUG=364250
TBR=dstockwell@chromium.org

Review URL: https://codereview.chromium.org/240573002

git-svn-id: svn://svn.chromium.org/blink/trunk@171809 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Treat flex items as selection roots.

Blink paints "selection gaps" that extend the selection to the bounds of the selection root.

If the selection spans two flex items, and the selection root is the RenderBody, the selection gap for the first item is painted on top of the second item, obscuring its text.

By making each flex item a selection root, the selection gap is painted only up to the bounds of the flex item.  This is the logic we use for table cells and positioned objects.

BUG=167341

Review URL: https://codereview.chromium.org/231793006

git-svn-id: svn://svn.chromium.org/blink/trunk@171810 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark http/tests/security/webgl-remote-read-remote-image-blocked-no-crossorigin.html as flaky

Mark the test http/tests/security/webgl-remote-read-remote-image-blocked-no-crossorigin.html
as flaky (timeout) on Mac and Win.

TBR=sigbjornf@opera.com
BUG=364267

Review URL: https://codereview.chromium.org/239153010

git-svn-id: svn://svn.chromium.org/blink/trunk@171811 bbb929c8-8fbe-4397-9dbb-9b2b20218538