ozone: events: Centralize & document our NativeEvent woes

ozone: events: Centralize & document our NativeEvent woes

The "conversion" from NativeEvent to ui::Event logically belongs in the
PlatformWindow, just prior to dispatch into aura. This is where the
analogous process happens for other platforms such as X11.

So do it there, using a helper function, and write a blurb about why we
need to do this (short answer: for compatibility with existing code,
while we working on fixing that code).

BUG=none
TEST=chrome --ozone-platform=caca, dri
NOTRY=true

Committed: https://crrev.com/25bd046f61399aa062cec49bbde50e1435202bca
Cr-Commit-Position: refs/heads/master@{#294599}

[spang, 2014-09-11 20:04:44]

spang@chromium.org changed reviewers:
+ kpschoedel@chromium.org

[kpschoedel, 2014-09-11 21:23:20]

LGTM

https://codereview.chromium.org/566673003/diff/1/ui/events/ozone/events_ozone.h
File ui/events/ozone/events_ozone.h (right):

https://codereview.chromium.org/566673003/diff/1/ui/events/ozone/events_ozone...
ui/events/ozone/events_ozone.h:28: //   "native" version of the event is
unmodified.
… and some code depends (for at least little longer) on the native event being
*modified* by event rewriting. Joy.

[spang, 2014-09-12 16:05:01]

The CQ bit was checked by spang@chromium.org

[commit-bot: I haz the power, 2014-09-12 16:06:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/566673003/1

[commit-bot: I haz the power, 2014-09-12 16:08:46]

Committed patchset #1 (id:1) as bb06109b864c2d4b6c11578c1bc338f36b61cb79

[commit-bot: I haz the power, 2014-09-12 16:12:15]

Patchset 1 (id:??) landed as
https://crrev.com/25bd046f61399aa062cec49bbde50e1435202bca
Cr-Commit-Position: refs/heads/master@{#294599}