Notify Blink to suppress frame requests during BeginMainFrame

Notify Blink to suppress frame requests during BeginMainFrame

This change fixes a performance regression where main thread frames were
being continuously requested during composited animations.
This is a temporary workaround that tells Blink when BeginMainFrame is
active and it should not be requesting new frames for visual updates.

BUG=704763
Review-Url: https://codereview.chromium.org/2791223002
Cr-Commit-Position: refs/heads/master@{#462022}
(cherry picked from commit 317a8e0e26459f401312043fa99ed8e17b1b24a4)

Review-Url: https://codereview.chromium.org/2813543003 .
Cr-Commit-Position: refs/branch-heads/3029@{#662}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/09fcbb12123dc079d446c48158ab228d8b2f5952

[alancutter (OOO until 2018), 2017-04-11 04:19:00]

Description was changed from

==========
Notify Blink to suppress frame requests during BeginMainFrame

This change fixes a performance regression where main thread frames were
being continuously requested during composited animations.
This is a temporary workaround that tells Blink when BeginMainFrame is
active and it should not be requesting new frames for visual updates.

BUG=704763

Review-Url: https://codereview.chromium.org/2791223002
Cr-Commit-Position: refs/heads/master@{#462022}
(cherry picked from commit 317a8e0e26459f401312043fa99ed8e17b1b24a4)
==========

to

==========
Notify Blink to suppress frame requests during BeginMainFrame

This change fixes a performance regression where main thread frames were
being continuously requested during composited animations.
This is a temporary workaround that tells Blink when BeginMainFrame is
active and it should not be requesting new frames for visual updates.

BUG=704763

Review-Url: https://codereview.chromium.org/2791223002
Cr-Commit-Position: refs/heads/master@{#462022}
(cherry picked from commit 317a8e0e26459f401312043fa99ed8e17b1b24a4)

Review-Url: https://codereview.chromium.org/2813543003 .
Cr-Commit-Position: refs/branch-heads/3029@{#662}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/09fcbb12123dc079d446c48158ab...
==========

[alancutter (OOO until 2018), 2017-04-11 04:19:03]

Committed patchset #1 (id:1) manually as
09fcbb12123dc079d446c48158ab228d8b2f5952.