Remove synchronous compositeAndReadback() from WebLayerTreeView.

Depends on: https://codereview.chromium.org/264713014/

R=abarth
BUG=251936

Review URL: https://codereview.chromium.org/276753002

git-svn-id: svn://svn.chromium.org/blink/trunk@173804 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a script to audit RuntimeEnabledFeatures.in

Also shows history of when features were added/removed.

This could also be taught to show what features have been
abandoned or have not changed in several months, but that's
a v2 feature for now.

BUG=371746

Review URL: https://codereview.chromium.org/275213002

git-svn-id: svn://svn.chromium.org/blink/trunk@173805 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add support for 'allow-orientation-lock' sandboxing directive

Add support for 'allow-orientation-lock' sandboxing directive when parsing
sandboxing directives:
https://w3c.github.io/screen-orientation/#dfn-sandboxed-orientation-lock-browsing-context-flag

Also throw an SecurityError DOMException if screen.lockOrientation() is called
on a Document whose active sandboxing flag set has the sandboxed orientation
lock browsing context flag set, as per the latest Screen Orientation API: 
https://w3c.github.io/screen-orientation/#dfn-apply-an-orientation-lock

R=abarth@chromium.org
BUG=162827
TEST=screen_orientation/lockOrientation-sandboxed-iframe.html

Review URL: https://codereview.chromium.org/272213002

git-svn-id: svn://svn.chromium.org/blink/trunk@173806 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Auto-rebaseline for r173782

http://src.chromium.org/viewvc/blink?view=revision&revision=173782

TBR=ojan@chromium.org

Review URL: https://codereview.chromium.org/279973006

git-svn-id: svn://svn.chromium.org/blink/trunk@173807 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Auto-rebaseline for r173773

http://src.chromium.org/viewvc/blink?view=revision&revision=173773

BUG=361729
TBR=danakj@chromium.org

Review URL: https://codereview.chromium.org/278163002

git-svn-id: svn://svn.chromium.org/blink/trunk@173808 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix bug in gmail where chat moles blink upon opening.

The reason for the blinking is a chicken-egg bug where we composite
the iframe contents, but not the iframe in the parent page. In theory
that never happens because anytime something inside the iframe
gets composited for non-overlap reasons, we tell the parent page
inside of style recalc to composite the iframe in the ChickenEggHacks
codepath of RenderLayerCompositor::updateLayerCompositingState. But when
it happens inside of compositing update (i.e. due to overlap), we miss a frame.

That theory turned out to be false in the case of compositing things
that are visibility:hidden. The overlap testing would think that
the element was going to be composited, and would add it to the
overlap test rects. But then when we got to compositing the
iframe, we'd check that it was visibility:hidden and not composite it.
So we'd end up with an iframe whose contents were composited
only for overlap reasons.

The fix is to use the same check in both the overlap testing
and in the test for whether an element should allocate a
CompositedLayerMapping. Specifically, the overlap testing
should also test if the subtree is invisible.

This fix isn't totally awesome in that it doesn't future-proof
against bugs like this getting added in the future.
I couldn't think of a good assert to add.

BUG=368388,366607

Review URL: https://codereview.chromium.org/278123002

git-svn-id: svn://svn.chromium.org/blink/trunk@173809 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add methods to set layer squashing. This will allow us to turn it on in via the commandline.

BUG=

Review URL: https://codereview.chromium.org/276963002

git-svn-id: svn://svn.chromium.org/blink/trunk@173810 bbb929c8-8fbe-4397-9dbb-9b2b20218538