Ensure that we consistently check contains: paint for fixed position containment.

Ensure that we consistently check contains: paint for fixed position containment.

contains: paint; should contain fixed position descendants, however we had only
updated this check in one place while we have many other places in the code
which simply checked for having transform related properties. This patch
attempts to unify all of these code paths to call through
ComputedStyle::canContainFixedPositionObjects.

TEST=fast/css/containment/paint-containment-with-fixed-position-scrolled.html, LayoutGeometryMapTest.ContainsFixedPositionTest, MapCoordinatesTest.FixedPosInTransform, MapCoordinatesTest.FixedPosInContainPaint
BUG=619999
Review-Url: https://codereview.chromium.org/2173963002
Cr-Commit-Position: refs/heads/master@{#408002}
(cherry picked from commit 139b50e91d0d86ad4ee31957a003dad264f38435)

Committed: https://chromium.googlesource.com/chromium/src/+/155dfcd5829342d0e52865e8dbd7c501f3ddeef1

[flackr, 2016-07-29 14:49:16]

Description was changed from

==========
Ensure that we consistently check contains: paint for fixed position
containment.

contains: paint; should contain fixed position descendants, however we had only
updated this check in one place while we have many other places in the code
which simply checked for having transform related properties. This patch
attempts to unify all of these code paths to call through
ComputedStyle::canContainFixedPositionObjects.

TEST=fast/css/containment/paint-containment-with-fixed-position-scrolled.html,
LayoutGeometryMapTest.ContainsFixedPositionTest,
MapCoordinatesTest.FixedPosInTransform,
MapCoordinatesTest.FixedPosInContainPaint
BUG=619999

Review-Url: https://codereview.chromium.org/2173963002
Cr-Commit-Position: refs/heads/master@{#408002}
(cherry picked from commit 139b50e91d0d86ad4ee31957a003dad264f38435)
==========

to

==========
Ensure that we consistently check contains: paint for fixed position
containment.

contains: paint; should contain fixed position descendants, however we had only
updated this check in one place while we have many other places in the code
which simply checked for having transform related properties. This patch
attempts to unify all of these code paths to call through
ComputedStyle::canContainFixedPositionObjects.

TEST=fast/css/containment/paint-containment-with-fixed-position-scrolled.html,
LayoutGeometryMapTest.ContainsFixedPositionTest,
MapCoordinatesTest.FixedPosInTransform,
MapCoordinatesTest.FixedPosInContainPaint
BUG=619999

Review-Url: https://codereview.chromium.org/2173963002
Cr-Commit-Position: refs/heads/master@{#408002}
(cherry picked from commit 139b50e91d0d86ad4ee31957a003dad264f38435)

Committed:
https://chromium.googlesource.com/chromium/src/+/155dfcd5829342d0e52865e8dbd7...
==========

[flackr, 2016-07-29 14:49:17]

Committed patchset #1 (id:1) manually as
155dfcd5829342d0e52865e8dbd7c501f3ddeef1.