[Mac] Opt browser window controller out of being a touch bar provider

[Mac] Opt browser window controller out of being a touch bar provider

Currently, on touch bar Macs, the system retains a reference to every
object it finds that conforms to the NSTouchBarProvider protocol, which
includes NSWindowController. If the user tries to quit Chrome when it
isn't foregrounded (for example, from the Dock icon context menu), these
references are never released, which means the browser window never
deallocs.

Since all browser windows being closed is a precondition of quitting,
Chrome never quits. There are a few private mechanisms to force the
touch bar to update its providers, but no matter what, the references
aren't released until Chrome is foregrounded.

This change effectively opts the window controller out of being a
touch bar provider which prevents it from being retained by the
touch bar mechanism in the first place.

BUG=667274
Committed: https://crrev.com/0098a25b70b91b23e87a4644e30722ba151e66e2
Cr-Commit-Position: refs/heads/master@{#435759}

[lgrey, 2016-12-01 20:34:51]

lgrey@chromium.org changed reviewers:
+ rsesek@chromium.org

[lgrey, 2016-12-01 20:34:52]

PTAL :)

[Robert Sesek, 2016-12-01 21:23:05]

LGTM w/ a nit. Nice trick :)

https://codereview.chromium.org/2550463002/diff/1/chrome/browser/ui/cocoa/bro...
File chrome/browser/ui/cocoa/browser_window_controller.mm (right):

https://codereview.chromium.org/2550463002/diff/1/chrome/browser/ui/cocoa/bro...
chrome/browser/ui/cocoa/browser_window_controller.mm:446: -
(BOOL)conformsToProtocol:(Protocol* )protocol {
nit: extra space after *

[lgrey, 2016-12-01 22:47:22]

The CQ bit was checked by lgrey@chromium.org

[lgrey, 2016-12-01 22:47:22]

The patchset sent to the CQ was uploaded after l-g-t-m from rsesek@chromium.org
Link to the patchset: https://codereview.chromium.org/2550463002/#ps20001
(title: "Formatting and added radar number")

[commit-bot: I haz the power, 2016-12-01 22:47:57]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-01 23:34:11]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1480632442459820,
"parent_rev": "458c7d0562b43a807e2089380deefdf7f05a1273", "commit_rev":
"b87b65bcea7eaab6f63d7afaea33180a3face183"}

[commit-bot: I haz the power, 2016-12-01 23:34:42]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-12-01 23:38:50]

Description was changed from

==========
[Mac] Opt browser window controller out of being a touch bar provider

Currently, on touch bar Macs, the system retains a reference to every
object it finds that conforms to the NSTouchBarProvider protocol, which
includes NSWindowController. If the user tries to quit Chrome when it
isn't foregrounded (for example, from the Dock icon context menu), these
references are never released, which means the browser window never
deallocs.

Since all browser windows being closed is a precondition of quitting,
Chrome never quits. There are a few private mechanisms to force the
touch bar to update its providers, but no matter what, the references
aren't released until Chrome is foregrounded.

This change effectively opts the window controller out of being a
touch bar provider which prevents it from being retained by the
touch bar mechanism in the first place.

BUG=667274
==========

to

==========
[Mac] Opt browser window controller out of being a touch bar provider

Currently, on touch bar Macs, the system retains a reference to every
object it finds that conforms to the NSTouchBarProvider protocol, which
includes NSWindowController. If the user tries to quit Chrome when it
isn't foregrounded (for example, from the Dock icon context menu), these
references are never released, which means the browser window never
deallocs.

Since all browser windows being closed is a precondition of quitting,
Chrome never quits. There are a few private mechanisms to force the
touch bar to update its providers, but no matter what, the references
aren't released until Chrome is foregrounded.

This change effectively opts the window controller out of being a
touch bar provider which prevents it from being retained by the
touch bar mechanism in the first place.

BUG=667274

Committed: https://crrev.com/0098a25b70b91b23e87a4644e30722ba151e66e2
Cr-Commit-Position: refs/heads/master@{#435759}
==========

[commit-bot: I haz the power, 2016-12-01 23:38:51]

Patchset 2 (id:??) landed as
https://crrev.com/0098a25b70b91b23e87a4644e30722ba151e66e2
Cr-Commit-Position: refs/heads/master@{#435759}