Revert of Remove a frame of delay on main-thread FlingStart.

Revert of Remove a frame of delay on main-thread FlingStart. (patchset #1 id:1 of https://codereview.chromium.org/2908073008/ )

Reason for revert:
Possible cause of flakiness in fast/events/touch/gesture/pad-gesture-fling.html ; see e.g. https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Mac10.11%20%28dbg%29/8992 .

Original issue's description:
> Remove a frame of delay on main-thread FlingStart.
> 
> Main-thread flings were waiting for the first frame of animation to
> populate the start timestamp, and only on the second frame would they
> start animating.  But the start timestamp is included in the FlingStart
> event, so there's no need for this (perhaps it was written that way for
> historical reasons when the event timestamp wasn't populated properly).
> 
> This problem was extremely noticeable in prototype of middle-click autoscroll
> that issues a FlingStart on every MouseMove to change velocity, but
> the fix should also benefit touchscreen and touchpad flings slightly.
> 
> BUG=727964
> 
> Review-Url: https://codereview.chromium.org/2908073008
> Cr-Commit-Position: refs/heads/master@{#475984}
> Committed: https://chromium.googlesource.com/chromium/src/+/3562f1b7410b884e07bbd2fc75cfee7e96ed2a41

TBR=jbroman@chromium.org,dtapuska@chromium.org,aelias@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=727964
Review-Url: https://codereview.chromium.org/2917823003
Cr-Commit-Position: refs/heads/master@{#476181}
Committed: https://chromium.googlesource.com/chromium/src/+/0c284454162c7b36d587707af42828f41336904f

[Peter Kasting, 2017-06-01 03:54:51]

The CQ bit was checked by pkasting@chromium.org

[Peter Kasting, 2017-06-01 03:54:51]

Created Revert of Remove a frame of delay on main-thread FlingStart.

[commit-bot: I haz the power, 2017-06-01 03:55:10]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-01 03:55:29]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496289291083500, "parent_rev":
"769ddd4b023df77418758c46bd166a448949ec3f", "commit_rev":
"0c284454162c7b36d587707af42828f41336904f"}

[commit-bot: I haz the power, 2017-06-01 03:55:38]

Description was changed from

==========
Revert of Remove a frame of delay on main-thread FlingStart. (patchset #1 id:1
of https://codereview.chromium.org/2908073008/ )

Reason for revert:
Possible cause of flakiness in fast/events/touch/gesture/pad-gesture-fling.html
; see e.g.
https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Mac10.11%20%2...
.

Original issue's description:
> Remove a frame of delay on main-thread FlingStart.
> 
> Main-thread flings were waiting for the first frame of animation to
> populate the start timestamp, and only on the second frame would they
> start animating.  But the start timestamp is included in the FlingStart
> event, so there's no need for this (perhaps it was written that way for
> historical reasons when the event timestamp wasn't populated properly).
> 
> This problem was extremely noticeable in prototype of middle-click autoscroll
> that issues a FlingStart on every MouseMove to change velocity, but
> the fix should also benefit touchscreen and touchpad flings slightly.
> 
> BUG=727964
> 
> Review-Url: https://codereview.chromium.org/2908073008
> Cr-Commit-Position: refs/heads/master@{#475984}
> Committed:
https://chromium.googlesource.com/chromium/src/+/3562f1b7410b884e07bbd2fc75cf...

TBR=jbroman@chromium.org,dtapuska@chromium.org,aelias@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=727964
==========

to

==========
Revert of Remove a frame of delay on main-thread FlingStart. (patchset #1 id:1
of https://codereview.chromium.org/2908073008/ )

Reason for revert:
Possible cause of flakiness in fast/events/touch/gesture/pad-gesture-fling.html
; see e.g.
https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Mac10.11%20%2...
.

Original issue's description:
> Remove a frame of delay on main-thread FlingStart.
> 
> Main-thread flings were waiting for the first frame of animation to
> populate the start timestamp, and only on the second frame would they
> start animating.  But the start timestamp is included in the FlingStart
> event, so there's no need for this (perhaps it was written that way for
> historical reasons when the event timestamp wasn't populated properly).
> 
> This problem was extremely noticeable in prototype of middle-click autoscroll
> that issues a FlingStart on every MouseMove to change velocity, but
> the fix should also benefit touchscreen and touchpad flings slightly.
> 
> BUG=727964
> 
> Review-Url: https://codereview.chromium.org/2908073008
> Cr-Commit-Position: refs/heads/master@{#475984}
> Committed:
https://chromium.googlesource.com/chromium/src/+/3562f1b7410b884e07bbd2fc75cf...

TBR=jbroman@chromium.org,dtapuska@chromium.org,aelias@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=727964

Review-Url: https://codereview.chromium.org/2917823003
Cr-Commit-Position: refs/heads/master@{#476181}
Committed:
https://chromium.googlesource.com/chromium/src/+/0c284454162c7b36d587707af428...
==========

[commit-bot: I haz the power, 2017-06-01 03:55:39]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/0c284454162c7b36d587707af428...