Restore simple fling status bookkeeping

Restore simple fling status bookkeeping

Recently, an active fling counter was introduced to track whether a
fling was active in the renderer. This was useful both for filtering
fling cancel events as well as signalling the end of a fling gesture
for telemetry purposes.

However, there appear to be gaps in the fling accounting that don't
appear in telemetry but do appear in the wild, causing issues with
fling-related tap suppression logic. Restore the previous fling
bookkeeping for the GestureEventQueue until the in-flight fling
count is correct for all gesture types.

BUG=483037
Committed: https://crrev.com/a4bcf3d1bd4294fb08d70974a156523720d926d0
Cr-Commit-Position: refs/heads/master@{#327993}

[jdduke (slow), 2015-05-01 19:35:38]

jdduke@chromium.org changed reviewers:
+ miletus@chromium.org

[jdduke (slow), 2015-05-01 19:35:39]

miletus@: Mind taking a look? This is basically a straightforward revert of
https://codereview.chromium.org/1074553002/ and
https://codereview.chromium.org/1053823002/, and a partial revert of
https://codereview.chromium.org/1003023002. I'd split them up and do individual
reverts, but then cherry-picking gets messy and there were some changes in the
last patch that we need to preserve.

[Yufeng Shen (Slow to review), 2015-05-01 20:01:55]

On 2015/05/01 19:35:39, jdduke wrote:
> miletus@: Mind taking a look? This is basically a straightforward revert of
> https://codereview.chromium.org/1074553002/ and
> https://codereview.chromium.org/1053823002/, and a partial revert of
> https://codereview.chromium.org/1003023002. I'd split them up and do
individual
> reverts, but then cherry-picking gets messy and there were some changes in the
> last patch that we need to preserve.

just want to double check that for crbug.com/474882, 
https://codereview.chromium.org/1053823002/  is the cause and 
https://codereview.chromium.org/1074553002/  is the fix
so reverting both we won't see the problem in 474882 right ?

[jdduke (slow), 2015-05-01 20:19:34]

On 2015/05/01 20:01:55, Yufeng Shen wrote:
> On 2015/05/01 19:35:39, jdduke wrote:
> > miletus@: Mind taking a look? This is basically a straightforward revert of
> > https://codereview.chromium.org/1074553002/ and
> > https://codereview.chromium.org/1053823002/, and a partial revert of
> > https://codereview.chromium.org/1003023002. I'd split them up and do
> individual
> > reverts, but then cherry-picking gets messy and there were some changes in
the
> > last patch that we need to preserve.
> 
> just want to double check that for crbug.com/474882, 
> https://codereview.chromium.org/1053823002/  is the cause and 
> https://codereview.chromium.org/1074553002/  is the fix
> so reverting both we won't see the problem in 474882 right ?

https://codereview.chromium.org/1003023002 was the original cause, those 2
patches were followup. But I'm reverting the portion of
https://codereview.chromium.org/1003023002 that caused the issue (fling
bookkeeping in the GestureEventQueue), which was the tap suppression problem
(the same reason we need to revert this patch generally for CrOS touchpad
flings).

[Yufeng Shen (Slow to review), 2015-05-01 20:43:25]

On 2015/05/01 20:19:34, jdduke wrote:
> On 2015/05/01 20:01:55, Yufeng Shen wrote:
> > On 2015/05/01 19:35:39, jdduke wrote:
> > > miletus@: Mind taking a look? This is basically a straightforward revert
of
> > > https://codereview.chromium.org/1074553002/ and
> > > https://codereview.chromium.org/1053823002/, and a partial revert of
> > > https://codereview.chromium.org/1003023002. I'd split them up and do
> > individual
> > > reverts, but then cherry-picking gets messy and there were some changes in
> the
> > > last patch that we need to preserve.
> > 
> > just want to double check that for crbug.com/474882, 
> > https://codereview.chromium.org/1053823002/  is the cause and 
> > https://codereview.chromium.org/1074553002/  is the fix
> > so reverting both we won't see the problem in 474882 right ?
> 
> https://codereview.chromium.org/1003023002 was the original cause, those 2
> patches were followup. But I'm reverting the portion of
> https://codereview.chromium.org/1003023002 that caused the issue (fling
> bookkeeping in the GestureEventQueue), which was the tap suppression problem
> (the same reason we need to revert this patch generally for CrOS touchpad
> flings).

got it. lgtm.

[jdduke (slow), 2015-05-01 21:02:28]

The CQ bit was checked by jdduke@chromium.org

[commit-bot: I haz the power, 2015-05-01 21:03:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1113143002/60001

[commit-bot: I haz the power, 2015-05-01 22:10:49]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-05-01 22:12:19]

Patchset 4 (id:??) landed as
https://crrev.com/a4bcf3d1bd4294fb08d70974a156523720d926d0
Cr-Commit-Position: refs/heads/master@{#327993}