[merge] CrOS: Don't paint tab-loading spinners in layers while in immersive fullscreen.

[merge] CrOS: Don't paint tab-loading spinners in layers while in immersive fullscreen.

This regressed in r362878 which didn't handle a case where animations
occur in immersive fullscreen.

To fix, disable layer-painting of tab spinners while in fullscreen.
In most cases the tab is hidden or animating; layers shouldn't
be used. When the tab strip is fully revealed we could use layers,
but the benefit isn't worth the extra logic.

TBR=tapted@chromium.org
BUG=591535
TEST=On CrOS, enter immersive fullscreen, reload a page, reveal the
tab strip while the page is still loading, then move the mouse down
to dismiss the tab strip. Ensure a frozen throbber doesn't stick
around, floating over the page.

Review URL: https://codereview.chromium.org/1758183002

Cr-Commit-Position: refs/heads/master@{#379140}
(cherry picked from commit fde5de1bc63b656dabaafef3e5b59badcc613a22)

Committed: https://chromium.googlesource.com/chromium/src/+/5196d5924deff29d6a4bbe4c6ccdc272a2686397

[tapted, 2016-03-09 08:14:42]

Description was changed from

==========
[merge] CrOS: Don't paint tab-loading spinners in layers while in immersive
fullscreen.

This regressed in r362878 which didn't handle a case where animations
occur in immersive fullscreen.

To fix, disable layer-painting of tab spinners while in fullscreen.
In most cases the tab is hidden or animating; layers shouldn't
be used. When the tab strip is fully revealed we could use layers,
but the benefit isn't worth the extra logic.

TBR=tapted@chromium.org
BUG=591535
TEST=On CrOS, enter immersive fullscreen, reload a page, reveal the
tab strip while the page is still loading, then move the mouse down
to dismiss the tab strip. Ensure a frozen throbber doesn't stick
around, floating over the page.

Review URL: https://codereview.chromium.org/1758183002

Cr-Commit-Position: refs/heads/master@{#379140}
(cherry picked from commit fde5de1bc63b656dabaafef3e5b59badcc613a22)
==========

to

==========
[merge] CrOS: Don't paint tab-loading spinners in layers while in immersive
fullscreen.

This regressed in r362878 which didn't handle a case where animations
occur in immersive fullscreen.

To fix, disable layer-painting of tab spinners while in fullscreen.
In most cases the tab is hidden or animating; layers shouldn't
be used. When the tab strip is fully revealed we could use layers,
but the benefit isn't worth the extra logic.

TBR=tapted@chromium.org
BUG=591535
TEST=On CrOS, enter immersive fullscreen, reload a page, reveal the
tab strip while the page is still loading, then move the mouse down
to dismiss the tab strip. Ensure a frozen throbber doesn't stick
around, floating over the page.

Review URL: https://codereview.chromium.org/1758183002

Cr-Commit-Position: refs/heads/master@{#379140}
(cherry picked from commit fde5de1bc63b656dabaafef3e5b59badcc613a22)

Committed:
https://chromium.googlesource.com/chromium/src/+/5196d5924deff29d6a4bbe4c6ccd...
==========

[tapted, 2016-03-09 08:14:45]

Committed patchset #1 (id:1) manually as
5196d5924deff29d6a4bbe4c6ccdc272a2686397 (presubmit successful).