ozone: evdev: Use kernel timestamps for mouse events

ozone: evdev: Use kernel timestamps for mouse events

This change adds a new constructor for ui::MouseEvent that takes an accurate
event time for use by the ozone evdev backend. For ui::MouseWheelEvent the
existing constructor was extended to include the timestamp and the existing
users updated.

For mouse moves in the generic handler the time of the EV_SYN message is
used as the time for the event. In events from the gesture library the end time
of the gesture is used. For purely synthetic events EventTimeForNow() is used
which uses the same time source (CLOCK_MONOTONIC) as evdev.

BUG=450341
TEST=Interactive testing on link_freon.
CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:linux_chromium_chromeos_ozone_rel_ng

Committed: https://crrev.com/c00e53cbb0968bd2fdf6e350f122bf67e5d7f468
Cr-Commit-Position: refs/heads/master@{#317091}

[robert.bradford, 2015-02-12 12:49:37]

robert.bradford@intel.com changed reviewers:
+ sadrul@chromium.org, spang@chromium.org

[robert.bradford, 2015-02-12 12:49:37]

robert.bradford@intel.com changed required reviewers:
+ sadrul@chromium.org, spang@chromium.org

[robert.bradford, 2015-02-12 12:49:38]

spang@chromium.org: Please take a look at ui/events/ozone changes. I removed
some of your TODOs in the process. For the times from the gesture library I used
the end time, I think that makes sense but am happy to use the start time (or
the mean?)

sadrul@chromium.org: Please review changes in ui/events and
content/browser/renderer_host. As per the last review (for KeyEvents) I extended
an existing ctor for the MouseWheelEvent however that was impractical for the
MouseEvent as code search says there are 320 references to that synthetic ctor.

Thanks!

[spang, 2015-02-12 21:27:06]

Just one comment: stime_t is just a double, should be no need to const& it.
Otherwise lgtm

On 2015/02/12 12:49:38, robert.bradford wrote:
> mailto:spang@chromium.org: Please take a look at ui/events/ozone changes. I
removed
> some of your TODOs in the process. For the times from the gesture library I
used
> the end time, I think that makes sense but am happy to use the start time (or
> the mean?)

end time sounds right, thanks.

> 
> mailto:sadrul@chromium.org: Please review changes in ui/events and
> content/browser/renderer_host. As per the last review (for KeyEvents) I
extended
> an existing ctor for the MouseWheelEvent however that was impractical for the
> MouseEvent as code search says there are 320 references to that synthetic
ctor.

I think sadrul wants to limit the number of constructors. We should be able to
get it landed even with many mechanical changes.

[robert.bradford, 2015-02-19 15:50:23]

New patchsets have been uploaded after l-g-t-m from spang@chromium.org

[robert.bradford, 2015-02-19 15:55:53]

Updated version rebased on top of the ctor change patch.

sadrul@: can you review the addition of the time_stamp to MouseWheelEvent

spang@: fixed the stime issue you highlighted.

Thanks!

[sadrul, 2015-02-19 17:23:20]

https://codereview.chromium.org/889673004/diff/20001/ui/events/event.cc
File ui/events/event.cc (right):

https://codereview.chromium.org/889673004/diff/20001/ui/events/event.cc#newco...
ui/events/event.cc:497: set_time_stamp(time_stamp);
Is this necessary?

[robert.bradford, 2015-02-19 17:30:44]

https://codereview.chromium.org/889673004/diff/20001/ui/events/event.cc
File ui/events/event.cc (right):

https://codereview.chromium.org/889673004/diff/20001/ui/events/event.cc#newco...
ui/events/event.cc:497: set_time_stamp(time_stamp);
On 2015/02/19 17:23:20, sadrul wrote:
> Is this necessary?

Whoops, this was necessary in the old version (before MouseEvent ctor was
modified) but not now. Removed in the latest patch version.

Thanks!

[sadrul, 2015-02-19 17:31:15]

lgtm

[spang, 2015-02-19 17:40:29]

lgtm

[robert.bradford, 2015-02-19 18:00:11]

The CQ bit was checked by robert.bradford@intel.com

[commit-bot: I haz the power, 2015-02-19 18:01:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/889673004/40001

[commit-bot: I haz the power, 2015-02-19 19:13:54]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-19 19:15:16]

Patchset 3 (id:??) landed as
https://crrev.com/c00e53cbb0968bd2fdf6e350f122bf67e5d7f468
Cr-Commit-Position: refs/heads/master@{#317091}