Disallow throttling while running requestAnimationFrame callbacks

Disallow throttling while running requestAnimationFrame callbacks

If a requestAnimationFrame callback tries to do a synchronous style
computation in another frame which is currently throttled, this fails
because throttling is allowed for the entire BeginMainFrame, which
includes running rAF callbacks as a substep.

This patch fixes the issue by disallowing throttling while executing rAF
callbacks. Note that rAF callbacks for throttled frames are still
skipped.

BUG=607336
Review-Url: https://codereview.chromium.org/1994133002
Cr-Commit-Position: refs/heads/master@{#395054}
(cherry picked from commit afdf51c967149db6bd8d6a533886efc957435e18)

Committed: https://chromium.googlesource.com/chromium/src/+/6c49b69538a2b834e6e463195147ac239291672e

[Sami, 2016-05-23 11:35:48]

Description was changed from

==========
Disallow throttling while running requestAnimationFrame callbacks

If a requestAnimationFrame callback tries to do a synchronous style
computation in another frame which is currently throttled, this fails
because throttling is allowed for the entire BeginMainFrame, which
includes running rAF callbacks as a substep.

This patch fixes the issue by disallowing throttling while executing rAF
callbacks. Note that rAF callbacks for throttled frames are still
skipped.

BUG=607336

Review-Url: https://codereview.chromium.org/1994133002
Cr-Commit-Position: refs/heads/master@{#395054}
(cherry picked from commit afdf51c967149db6bd8d6a533886efc957435e18)
==========

to

==========
Disallow throttling while running requestAnimationFrame callbacks

If a requestAnimationFrame callback tries to do a synchronous style
computation in another frame which is currently throttled, this fails
because throttling is allowed for the entire BeginMainFrame, which
includes running rAF callbacks as a substep.

This patch fixes the issue by disallowing throttling while executing rAF
callbacks. Note that rAF callbacks for throttled frames are still
skipped.

BUG=607336

Review-Url: https://codereview.chromium.org/1994133002
Cr-Commit-Position: refs/heads/master@{#395054}
(cherry picked from commit afdf51c967149db6bd8d6a533886efc957435e18)

Committed:
https://chromium.googlesource.com/chromium/src/+/6c49b69538a2b834e6e463195147...
==========

[Sami, 2016-05-23 11:35:50]

Committed patchset #1 (id:1) manually as
6c49b69538a2b834e6e463195147ac239291672e.