Add a hack to set shouldPaint to true for force-composited iframes.

Add a hack to set shouldPaint to true for force-composited iframes.

This works around a FCB chicken-egg problem in which we are unable to properly
start painting floating iframes once they stop being composited.

BUG=610906
Review-Url: https://codereview.chromium.org/2009353003
Cr-Commit-Position: refs/heads/master@{#396287}
(cherry picked from commit 3e010d5a156f8420a7deaae243b9c9323517aef1)

Committed: https://chromium.googlesource.com/chromium/src/+/4ceaf2bd78a36291788f4291988611825ebbb84c

[chrishtr, 2016-05-31 21:28:46]

Description was changed from

==========
Add a hack to set shouldPaint to true for force-composited iframes.

This works around a FCB chicken-egg problem in which we are unable to properly
start painting floating iframes once they stop being composited.

BUG=610906

Review-Url: https://codereview.chromium.org/2009353003
Cr-Commit-Position: refs/heads/master@{#396287}
(cherry picked from commit 3e010d5a156f8420a7deaae243b9c9323517aef1)
==========

to

==========
Add a hack to set shouldPaint to true for force-composited iframes.

This works around a FCB chicken-egg problem in which we are unable to properly
start painting floating iframes once they stop being composited.

BUG=610906

Review-Url: https://codereview.chromium.org/2009353003
Cr-Commit-Position: refs/heads/master@{#396287}
(cherry picked from commit 3e010d5a156f8420a7deaae243b9c9323517aef1)

Committed:
https://chromium.googlesource.com/chromium/src/+/4ceaf2bd78a36291788f42919886...
==========

[chrishtr, 2016-05-31 21:28:47]

Committed patchset #1 (id:1) manually as
4ceaf2bd78a36291788f4291988611825ebbb84c.