Observe for window's (self) deletion during activation/focus change

Observe for window's (self) deletion during activation/focus change.

Added a windows destruction observer. It is use to observe
(detect) when an Aura Window or RenderWidgetHostViewAura is
deleted during execution of a member function because of
activation/focus change.

This fixes browser crashes when exiting fullscreen Flash with ESC.

BUG=197023
TEST=Press ESC when in full-screen Flash

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=189308

[Ben Goodger (Google), 2013-03-19 18:13:17]

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc
File ui/aura/window.cc (right):

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc#newcode997
ui/aura/window.cc:997: WindowDestructionObserver destruction_observer;
I think the API would be a little cleaner here if you just made this ctor take
the window, and you had a destroyed() accessor on it.

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc#newcode999
ui/aura/window.cc:999: const Window* copy_this = this;
then you wouldn't have to do things like this which are awkward

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc#newcode...
ui/aura/window.cc:1012: std::set<const Window*> child_already_processed;
you only fill this, but never actually use it.

[sschmitz, 2013-03-19 18:36:49]

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc
File ui/aura/window.cc (right):

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc#newcode997
ui/aura/window.cc:997: WindowDestructionObserver destruction_observer;
On 2013/03/19 18:13:17, Ben Goodger (Google) wrote:
> I think the API would be a little cleaner here if you just made this ctor take
> the window, and you had a destroyed() accessor on it.
Neat.
Done.

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc#newcode999
ui/aura/window.cc:999: const Window* copy_this = this;
On 2013/03/19 18:13:17, Ben Goodger (Google) wrote:
> then you wouldn't have to do things like this which are awkward

Done.

https://codereview.chromium.org/12929002/diff/16001/ui/aura/window.cc#newcode...
ui/aura/window.cc:1012: std::set<const Window*> child_already_processed;
On 2013/03/19 18:13:17, Ben Goodger (Google) wrote:
> you only fill this, but never actually use it.

I'm using the fact that set<>::insert() returns a pair where |second| is true if
the insert succeeded and false if the element already existed.

[Ben Goodger (Google), 2013-03-19 21:21:41]

https://codereview.chromium.org/12929002/diff/19001/ui/aura/window.cc
File ui/aura/window.cc (right):

https://codereview.chromium.org/12929002/diff/19001/ui/aura/window.cc#newcode998
ui/aura/window.cc:998: AddObserver(&destruction_observer);
WDO's ctor should just add the observer. Likewise its dtor should remove it (if
!destroyed_)

https://codereview.chromium.org/12929002/diff/19001/ui/aura/window.cc#newcode...
ui/aura/window.cc:1001: if (destruction_observer.destroyed())
... then the rest of this function is simply

return !destruction_observer.destroyed();

[sschmitz, 2013-03-19 22:12:13]

Done.

https://codereview.chromium.org/12929002/diff/19001/ui/aura/window.cc
File ui/aura/window.cc (right):

https://codereview.chromium.org/12929002/diff/19001/ui/aura/window.cc#newcode998
ui/aura/window.cc:998: AddObserver(&destruction_observer);
On 2013/03/19 21:21:41, Ben Goodger (Google) wrote:
> WDO's ctor should just add the observer. Likewise its dtor should remove it
(if
> !destroyed_)

Done.

https://codereview.chromium.org/12929002/diff/19001/ui/aura/window.cc#newcode...
ui/aura/window.cc:1001: if (destruction_observer.destroyed())
On 2013/03/19 21:21:41, Ben Goodger (Google) wrote:
> ... then the rest of this function is simply
> 
> return !destruction_observer.destroyed();

Done.

[Ben Goodger (Google), 2013-03-19 22:55:58]

lgtm

2 nits

https://codereview.chromium.org/12929002/diff/24001/ui/aura/window_destructio...
File ui/aura/window_destruction_observer.h (right):

https://codereview.chromium.org/12929002/diff/24001/ui/aura/window_destructio...
ui/aura/window_destruction_observer.h:25:
WindowDestructionObserver(aura::Window* window);
explicit

https://codereview.chromium.org/12929002/diff/24001/ui/aura/window_destructio...
ui/aura/window_destruction_observer.h:32: bool destroyed() const;
you can just inline this impl here

[sschmitz, 2013-03-19 23:11:06]

Thanks.

https://codereview.chromium.org/12929002/diff/24001/ui/aura/window_destructio...
File ui/aura/window_destruction_observer.h (right):

https://codereview.chromium.org/12929002/diff/24001/ui/aura/window_destructio...
ui/aura/window_destruction_observer.h:25:
WindowDestructionObserver(aura::Window* window);
On 2013/03/19 22:55:58, Ben Goodger (Google) wrote:
> explicit

Done.

https://codereview.chromium.org/12929002/diff/24001/ui/aura/window_destructio...
ui/aura/window_destruction_observer.h:32: bool destroyed() const;
On 2013/03/19 22:55:58, Ben Goodger (Google) wrote:
> you can just inline this impl here

Done.

[commit-bot: I haz the power, 2013-03-19 23:13:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sschmitz@chromium.org/12929002/38001

[commit-bot: I haz the power, 2013-03-20 14:06:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sschmitz@chromium.org/12929002/38001

[commit-bot: I haz the power, 2013-03-20 16:34:53]

Change committed as 189308