Fix three crashes in the recent tabs dialog.

Fix three crashes in the recent tabs dialog.

This fixes a crash in the recent tabs dialog when clicking on a recently
closed tab and clicking the dialog's "X" button almost simultaneously.

The crash happened because when "X" is clicked, the dialog would be
dismissed and the RecentTabsPage would be destroyed. Soon thereafter,
the click on the recently closed item would be processed and it would
try to use the RecentTabsPage object.

This CL fixes the crash by tracking whether the RecentTabsManager has
been destroyed and ignoring clicks that happen after destroy has been
called. This also fixes an identical crash with clicking a foreign
session tab, and a related (but rarer) crash where sync or sign-in
related events were being processed after the RecentTabsManager was
destroyed.

BUG=567891
Committed: https://crrev.com/7f87dbd5a96f0e29039285544428b5298cb22aa2
Cr-Commit-Position: refs/heads/master@{#365075}

[newt (away), 2015-12-11 22:23:54]

newt@chromium.org changed reviewers:
+ tedchoc@chromium.org

[newt (away), 2015-12-11 22:23:55]

I'll see your NPE fix, and raise you several more ;)

PTAL

[Ted C, 2015-12-12 00:16:41]

lgtm :-)

[newt (away), 2015-12-12 00:24:27]

The CQ bit was checked by newt@chromium.org

[commit-bot: I haz the power, 2015-12-12 00:27:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1521553004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1521553004/1

[commit-bot: I haz the power, 2015-12-12 02:38:22]

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

[commit-bot: I haz the power, 2015-12-12 02:38:23]

Try jobs failed on following builders:
  android_chromium_gn_compile_dbg on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  android_clang_dbg_recipe on tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  cast_shell_linux on tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  chromeos_daisy_chromium_compile_only_ng on tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_compile_dbg_ng on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)
  linux_chromium_gn_chromeos_rel on tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)

[newt (away), 2015-12-14 19:04:42]

The CQ bit was checked by newt@chromium.org

[commit-bot: I haz the power, 2015-12-14 19:05:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1521553004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1521553004/1

[commit-bot: I haz the power, 2015-12-14 19:48:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-14 19:49:03]

Description was changed from

==========
Fix three crashes in the recent tabs dialog.

This fixes a crash in the recent tabs dialog when clicking on a recently
closed tab and clicking the dialog's "X" button almost simultaneously.

The crash happened because when "X" is clicked, the dialog would be
dismissed and the RecentTabsPage would be destroyed. Soon thereafter,
the click on the recently closed item would be processed and it would
try to use the RecentTabsPage object.

This CL fixes the crash by tracking whether the RecentTabsManager has
been destroyed and ignoring clicks that happen after destroy has been
called. This also fixes an identical crash with clicking a foreign
session tab, and a related (but rarer) crash where sync or sign-in
related events were being processed after the RecentTabsManager was
destroyed.

BUG=567891
==========

to

==========
Fix three crashes in the recent tabs dialog.

This fixes a crash in the recent tabs dialog when clicking on a recently
closed tab and clicking the dialog's "X" button almost simultaneously.

The crash happened because when "X" is clicked, the dialog would be
dismissed and the RecentTabsPage would be destroyed. Soon thereafter,
the click on the recently closed item would be processed and it would
try to use the RecentTabsPage object.

This CL fixes the crash by tracking whether the RecentTabsManager has
been destroyed and ignoring clicks that happen after destroy has been
called. This also fixes an identical crash with clicking a foreign
session tab, and a related (but rarer) crash where sync or sign-in
related events were being processed after the RecentTabsManager was
destroyed.

BUG=567891

Committed: https://crrev.com/7f87dbd5a96f0e29039285544428b5298cb22aa2
Cr-Commit-Position: refs/heads/master@{#365075}
==========

[commit-bot: I haz the power, 2015-12-14 19:49:04]

Patchset 1 (id:??) landed as
https://crrev.com/7f87dbd5a96f0e29039285544428b5298cb22aa2
Cr-Commit-Position: refs/heads/master@{#365075}