Remove the MessageLoop::DestructionObserver from mojo bindings.

Remove the MessageLoop::DestructionObserver from mojo bindings.

Mojo connection error handlers running during browser shutdown have been
a cause of several crashes due to the error handlers running after their
dependency (e.g. a KeyedService or a RenderProcessHost) has shut down.
From a brief survey of users of StrongBinding, none appear to perform
any tear-down that is necessary during process shutdown. Further, the
vast majority of threads (and thread pools) run for close to the life of
the process, so any these connection error handlers will generally only
be triggered during shutdown. Thus, in production this causes slower,
less-stable browser shutdowns without any real benefit.

Additionally, SequencedTaskRunner does not have a MessageLoop and is not
expected to support a similar destruction observer. Thus, to improve
compatibility with future support for running mojo bindings on
SequencedTaskRunners, this removes MessageLoop::DestructionObserver from
mojo bindings.

BUG=678155
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2633053002
Cr-Commit-Position: refs/heads/master@{#447085}
Committed: https://chromium.googlesource.com/chromium/src/+/14e09ca425d1ee9572f69d29cdd00cff1a1b2bfc

[Sam McNally, 2017-01-15 22:46:42]

Description was changed from

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.
==========

to

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

[Sam McNally, 2017-01-15 22:50:41]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-15 22:50:52]

Dry run: 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, 2017-01-15 22:52:22]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-15 22:52:23]

Dry run: Try jobs failed on following builders:
  ios-device-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device-xcode-...)
  ios-simulator on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/bui...)
  ios-simulator-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator-xco...)

[Sam McNally, 2017-01-15 23:05:11]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-15 23:05:22]

Dry run: 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, 2017-01-15 23:19:52]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-15 23:19:53]

Dry run: Try jobs failed on following builders:
  chromeos_daisy_chromium_compile_only_ng on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromeos_daisy_...)
  linux_chromium_chromeos_ozone_rel_ng on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Sam McNally, 2017-01-15 23:39:27]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-15 23:39:38]

Dry run: 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, 2017-01-16 00:09:13]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-16 00:09:13]

Dry run: Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Sam McNally, 2017-01-16 04:21:56]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-16 04:22:06]

Dry run: 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, 2017-01-16 06:33:35]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-16 06:33:36]

Dry run: Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Sam McNally, 2017-01-16 23:54:19]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-16 23:54:32]

Dry run: 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, 2017-01-17 01:46:29]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-17 01:46:30]

Dry run: Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Sam McNally, 2017-01-18 07:13:53]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-18 07:14:11]

Dry run: 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, 2017-01-18 09:14:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-18 09:14:19]

Dry run: Try jobs failed on following builders:
  win_chromium_x64_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Sam McNally, 2017-01-20 00:27:15]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-20 00:27:57]

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

[Sam McNally, 2017-01-20 01:38:10]

The CQ bit was unchecked by sammc@chromium.org

[Sam McNally, 2017-01-23 05:51:20]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-23 05:51:34]

Dry run: 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, 2017-01-23 06:35:12]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-23 06:35:13]

Dry run: Try jobs failed on following builders:
  android_n5x_swarming_rel on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_n5x_...)

[Sam McNally, 2017-01-24 01:34:52]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 01:35:25]

Dry run: 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, 2017-01-24 01:39:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-24 01:39:11]

Dry run: Try jobs failed on following builders:
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  ios-device-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device-xcode-...)
  ios-simulator on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/bui...)
  ios-simulator-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator-xco...)
  mac_chromium_compile_dbg_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[Sam McNally, 2017-01-24 02:02:01]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 02:02:56]

Dry run: 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, 2017-01-24 02:14:35]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-24 02:14:37]

Dry run: Try jobs failed on following builders:
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  ios-simulator on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/bui...)

[Sam McNally, 2017-01-24 02:22:01]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 02:22:55]

Dry run: 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, 2017-01-24 02:31:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-24 02:31:26]

Dry run: Try jobs failed on following builders:
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  ios-device-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device-xcode-...)
  ios-simulator on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/bui...)
  ios-simulator-xcode-clang on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator-xco...)

[Sam McNally, 2017-01-24 03:48:55]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 03:49:20]

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

[Sam McNally, 2017-01-24 04:37:30]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 04:37:57]

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

[Sam McNally, 2017-01-24 04:41:27]

Patchset #11 (id:200001) has been deleted

[Sam McNally, 2017-01-24 04:41:47]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 04:42:09]

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

[Sam McNally, 2017-01-24 04:43:10]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 04:43:26]

Dry run: 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, 2017-01-24 05:19:01]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-24 05:19:02]

Dry run: Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Sam McNally, 2017-01-24 12:27:24]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 12:27:40]

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

[Sam McNally, 2017-01-24 12:28:46]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 12:28:52]

Dry run: 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, 2017-01-24 13:17:38]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-24 13:17:39]

Dry run: Try jobs failed on following builders:
  cast_shell_linux on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linu...)

[Sam McNally, 2017-01-24 23:12:35]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-24 23:15:06]

Dry run: 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, 2017-01-25 01:08:49]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-25 01:08:50]

Dry run: Try jobs failed on following builders:
  win_clang on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_clang/builds/...)

[Sam McNally, 2017-01-25 01:09:42]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-25 01:10:46]

Dry run: 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, 2017-01-25 01:47:57]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-25 01:47:58]

Dry run: Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Sam McNally, 2017-01-25 04:56:42]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-25 04:57:00]

Dry run: 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, 2017-01-25 05:11:56]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-25 05:11:58]

Dry run: Try jobs failed on following builders:
  chromeos_amd64-generic_chromium_compile_only_ng on
master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromeos_amd64-...)
  linux_chromium_chromeos_ozone_rel_ng on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Sam McNally, 2017-01-25 05:43:18]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-25 05:43:36]

Dry run: 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, 2017-01-25 07:02:05]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-25 07:02:06]

Dry run: Try jobs failed on following builders:
  mac_optional_gpu_tests_rel on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_optional_gpu_...)

[Sam McNally, 2017-01-25 07:21:12]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-25 07:21:32]

Dry run: 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, 2017-01-25 07:54:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-25 07:54:04]

Dry run: This issue passed the CQ dry run.

[Sam McNally, 2017-01-25 09:02:29]

Description was changed from

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

to

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.

Mojo connection error handlers running during browser shutdown have been
a cause of several crashes due to the error handlers running after their
dependency (e.g. a KeyedService or a RenderProcessHost) has shut down.
From a brief survey of users of StrongBinding, none appear to perform
any tear-down that is necessary during process shutdown. Further, the
vast majority of threads (and thread pools) run for close to the life of
the process, so any these connection error handlers will generally only
be triggered during shutdown. Thus, in production this causes slower,
less-stable browser shutdowns without any real benefit.

Additionally, SequencedTaskRunners do not have a MessageLoop and are not
expected to support a similar destruction observer. Thus, to improve
compatibility with future support for running mojo bindings on
SequencedTaskRunners, this removes MessageLoop::DestructionObserver from
mojo bindings.

BUG=678155
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

[Sam McNally, 2017-01-25 09:05:30]

Patchset #16 (id:320001) has been deleted

[Sam McNally, 2017-01-25 09:05:35]

Patchset #15 (id:300001) has been deleted

[Sam McNally, 2017-01-25 09:05:39]

Patchset #14 (id:280001) has been deleted

[Sam McNally, 2017-01-25 09:05:43]

Patchset #13 (id:260001) has been deleted

[Sam McNally, 2017-01-25 09:05:48]

Patchset #12 (id:240001) has been deleted

[Sam McNally, 2017-01-25 09:05:52]

Patchset #11 (id:220001) has been deleted

[Sam McNally, 2017-01-25 09:05:57]

Patchset #10 (id:180001) has been deleted

[Sam McNally, 2017-01-25 09:06:00]

Patchset #9 (id:160001) has been deleted

[Sam McNally, 2017-01-25 09:06:05]

Patchset #8 (id:140001) has been deleted

[Sam McNally, 2017-01-25 09:06:09]

Patchset #7 (id:120001) has been deleted

[Sam McNally, 2017-01-25 09:06:13]

Patchset #6 (id:100001) has been deleted

[Sam McNally, 2017-01-25 09:06:17]

Patchset #5 (id:80001) has been deleted

[Sam McNally, 2017-01-25 09:06:22]

Patchset #4 (id:60001) has been deleted

[Sam McNally, 2017-01-25 09:06:26]

Patchset #3 (id:40001) has been deleted

[Sam McNally, 2017-01-25 09:06:31]

Patchset #2 (id:20001) has been deleted

[Sam McNally, 2017-01-25 09:07:10]

Patchset #1 (id:1) has been deleted

[Sam McNally, 2017-01-25 09:54:53]

Description was changed from

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.

Mojo connection error handlers running during browser shutdown have been
a cause of several crashes due to the error handlers running after their
dependency (e.g. a KeyedService or a RenderProcessHost) has shut down.
From a brief survey of users of StrongBinding, none appear to perform
any tear-down that is necessary during process shutdown. Further, the
vast majority of threads (and thread pools) run for close to the life of
the process, so any these connection error handlers will generally only
be triggered during shutdown. Thus, in production this causes slower,
less-stable browser shutdowns without any real benefit.

Additionally, SequencedTaskRunners do not have a MessageLoop and are not
expected to support a similar destruction observer. Thus, to improve
compatibility with future support for running mojo bindings on
SequencedTaskRunners, this removes MessageLoop::DestructionObserver from
mojo bindings.

BUG=678155
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

to

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.

Mojo connection error handlers running during browser shutdown have been
a cause of several crashes due to the error handlers running after their
dependency (e.g. a KeyedService or a RenderProcessHost) has shut down.
From a brief survey of users of StrongBinding, none appear to perform
any tear-down that is necessary during process shutdown. Further, the
vast majority of threads (and thread pools) run for close to the life of
the process, so any these connection error handlers will generally only
be triggered during shutdown. Thus, in production this causes slower,
less-stable browser shutdowns without any real benefit.

Additionally, SequencedTaskRunner does not have a MessageLoop and is not
expected to support a similar destruction observer. Thus, to improve
compatibility with future support for running mojo bindings on
SequencedTaskRunners, this removes MessageLoop::DestructionObserver from
mojo bindings.

BUG=678155
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

[Sam McNally, 2017-01-25 10:33:32]

sammc@chromium.org changed reviewers:
+ rockot@chromium.org, yzshen@chromium.org

[yzshen1, 2017-01-25 17:13:52]

On 2017/01/25 10:33:33, Sam McNally wrote:

Overall this looks good.

Please add comments to Strong[Associated]Binding about this behavior.
And also send a mail to chromium-mojo@.

[yzshen1, 2017-01-25 17:27:05]

On 2017/01/25 17:13:52, yzshen1 wrote:
> On 2017/01/25 10:33:33, Sam McNally wrote:
> 
> Overall this looks good.
> 
> Please add comments to Strong[Associated]Binding about this behavior.
> And also send a mail to chromium-mojo@.

And please also remove the observer from
//src/mojo/android/system/watcher_impl.cc

[Sam McNally, 2017-01-26 23:28:15]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-26 23:29:30]

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

[Ken Rockot(use gerrit already), 2017-01-26 23:51:19]

LGTM!

[yzshen1, 2017-01-26 23:58:20]

LGTM with one nit.

https://codereview.chromium.org/2633053002/diff/360001/mojo/public/cpp/bindin...
File mojo/public/cpp/bindings/strong_associated_binding.h (right):

https://codereview.chromium.org/2633053002/diff/360001/mojo/public/cpp/bindin...
mojo/public/cpp/bindings/strong_associated_binding.h:33: // task runner that a
StrongBinding is bound on is stopped, the connection error
nit: StrongBinding -> StrongAssociatedBinding

[Sam McNally, 2017-01-27 03:56:26]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-27 03:57:03]

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

[Sam McNally, 2017-01-27 04:54:19]

sammc@chromium.org changed reviewers:
+ jbauman@chromium.org

[Sam McNally, 2017-01-27 04:54:20]

+jbauman for //gpu and //content/*/gpu (in particular the change to
content::BrowserGpuChannelHostFactory and its use from
content/browser/browser_main_loop.cc)

https://codereview.chromium.org/2633053002/diff/360001/mojo/public/cpp/bindin...
File mojo/public/cpp/bindings/strong_associated_binding.h (right):

https://codereview.chromium.org/2633053002/diff/360001/mojo/public/cpp/bindin...
mojo/public/cpp/bindings/strong_associated_binding.h:33: // task runner that a
StrongBinding is bound on is stopped, the connection error
On 2017/01/26 23:58:20, yzshen1 wrote:
> nit: StrongBinding -> StrongAssociatedBinding

Done.

[commit-bot: I haz the power, 2017-01-27 05:55:13]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-27 05:55:15]

Dry run: This issue passed the CQ dry run.

[jbauman, 2017-01-27 23:01:38]

gpu stuff lgtm

[Sam McNally, 2017-01-29 22:21:51]

The CQ bit was checked by sammc@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-01-29 22:22:04]

Dry run: 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, 2017-01-30 00:05:34]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-01-30 00:05:35]

Dry run: This issue passed the CQ dry run.

[Sam McNally, 2017-01-30 01:46:50]

sammc@chromium.org changed reviewers:
+ jam@chromium.org

[Sam McNally, 2017-01-30 01:46:51]

+jam for //content other than //content/*/gpu, //chrome, //ash and
//android_webview

[jam, 2017-01-30 18:02:25]

lgtm

[Sam McNally, 2017-01-30 21:58:41]

The CQ bit was checked by sammc@chromium.org

[Sam McNally, 2017-01-30 21:58:42]

The patchset sent to the CQ was uploaded after l-g-t-m from rockot@chromium.org,
yzshen@chromium.org, jbauman@chromium.org
Link to the patchset: https://codereview.chromium.org/2633053002/#ps440001
(title: "rebase")

[commit-bot: I haz the power, 2017-01-30 21:59:37]

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, 2017-01-30 22:07:37]

CQ is committing da patch.

Bot data: {"patchset_id": 440001, "attempt_start_ts": 1485813521378590,
"parent_rev": "29f5ca9855a1e292eb27bcfd07bb728c3faefde2", "commit_rev":
"14e09ca425d1ee9572f69d29cdd00cff1a1b2bfc"}

[commit-bot: I haz the power, 2017-01-30 22:08:14]

Description was changed from

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.

Mojo connection error handlers running during browser shutdown have been
a cause of several crashes due to the error handlers running after their
dependency (e.g. a KeyedService or a RenderProcessHost) has shut down.
From a brief survey of users of StrongBinding, none appear to perform
any tear-down that is necessary during process shutdown. Further, the
vast majority of threads (and thread pools) run for close to the life of
the process, so any these connection error handlers will generally only
be triggered during shutdown. Thus, in production this causes slower,
less-stable browser shutdowns without any real benefit.

Additionally, SequencedTaskRunner does not have a MessageLoop and is not
expected to support a similar destruction observer. Thus, to improve
compatibility with future support for running mojo bindings on
SequencedTaskRunners, this removes MessageLoop::DestructionObserver from
mojo bindings.

BUG=678155
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
==========

to

==========
Remove the MessageLoop::DestructionObserver from mojo bindings.

Mojo connection error handlers running during browser shutdown have been
a cause of several crashes due to the error handlers running after their
dependency (e.g. a KeyedService or a RenderProcessHost) has shut down.
From a brief survey of users of StrongBinding, none appear to perform
any tear-down that is necessary during process shutdown. Further, the
vast majority of threads (and thread pools) run for close to the life of
the process, so any these connection error handlers will generally only
be triggered during shutdown. Thus, in production this causes slower,
less-stable browser shutdowns without any real benefit.

Additionally, SequencedTaskRunner does not have a MessageLoop and is not
expected to support a similar destruction observer. Thus, to improve
compatibility with future support for running mojo bindings on
SequencedTaskRunners, this removes MessageLoop::DestructionObserver from
mojo bindings.

BUG=678155
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2633053002
Cr-Commit-Position: refs/heads/master@{#447085}
Committed:
https://chromium.googlesource.com/chromium/src/+/14e09ca425d1ee9572f69d29cdd0...
==========

[commit-bot: I haz the power, 2017-01-30 22:08:18]

Committed patchset #6 (id:440001) as
https://chromium.googlesource.com/chromium/src/+/14e09ca425d1ee9572f69d29cdd0...