aura: Add RootWindowObserver::OnKeyboardMappingChanged().

aura: Add RootWindowObserver::OnKeyboardMappingChanged().

This gives us a way to watch for changes to the keyboard
map.  I also noticed that we were dropping MappingNotify
events since they don't have an associated window; with this
change, we now send them to all of the dispatchers instead.

BUG=121012
TEST=manual: checked that observer method is called when i run xmodmap

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=130009

[sadrul, 2012-03-30 22:54:13]

LGTM.

Will there need to be a OnMouseButtonMappingChanged too?

[Daniel Erat, 2012-03-30 22:58:07]

On 2012/03/30 22:54:13, sadrul wrote:
> LGTM.
> 
> Will there need to be a OnMouseButtonMappingChanged too?

I hope not.  In a perfect world, everything downstream of RootWindowHostLinux
can get what it needs from the aura::Event without needing to reach into the
native X event -- I think that this is the case for mouse buttons 1-3.

For http://crbug.com/121012, we need to mess around with the native event,
including checking if Mod4Mask (which has no representation in ui/base) is set. 
The change that I'm taking over from yusukes@
(http://codereview.chromium.org/9854025/) needs to convert keycodes to keysyms
and vice versa, and it needs to refresh that mapping when the keyboard map
changes.

[sadrul, 2012-03-30 23:10:53]

On 2012/03/30 22:58:07, Daniel Erat wrote:
> On 2012/03/30 22:54:13, sadrul wrote:
> > LGTM.
> > 
> > Will there need to be a OnMouseButtonMappingChanged too?
> 
> I hope not.  In a perfect world, everything downstream of RootWindowHostLinux
> can get what it needs from the aura::Event without needing to reach into the
> native X event -- I think that this is the case for mouse buttons 1-3.

There's also ui::GetMappedButton that will hopefully handle all the buttons.

> 
> For http://crbug.com/121012, we need to mess around with the native event,
> including checking if Mod4Mask (which has no representation in ui/base) is
set. 
> The change that I'm taking over from yusukes@
> (http://codereview.chromium.org/9854025/) needs to convert keycodes to keysyms
> and vice versa, and it needs to refresh that mapping when the keyboard map
> changes.

I see. Thanks for explaining.

[commit-bot: I haz the power, 2012-03-30 23:18:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/derat@chromium.org/9958036/5001

[commit-bot: I haz the power, 2012-03-30 23:18:44]

Presubmit check for 9958036-5001 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit ERRORS **
Missing LGTM from an OWNER for files in these directories:
    ui/aura

[Daniel Erat, 2012-03-30 23:20:39]

+sky for ui/aura approval

[sky, 2012-03-30 23:22:02]

LGTM

I wonder why we aren't using an ObserverList.

[commit-bot: I haz the power, 2012-03-30 23:59:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/derat@chromium.org/9958036/5001

[commit-bot: I haz the power, 2012-03-31 00:33:31]

Try job failure for 9958036-5001 (retry) on win_rel for step "compile" (clobber
build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...