Remove destruction observer from file_path_watcher_win.cc

Remove destruction observer from file_path_watcher_win.cc

Now that the FilePathWatcher::~FilePathWatcher() is called on the same
sequence as FilePathWatcher::Watch() (see
https://codereview.chromium.org/2438913003/), the work done in
FilePathWatcherImpl::WillDestroyCurrentMessageLoop() can safely be
moved to FilePathWatcherImpl::Cancel().

BUG=650318
Committed: https://crrev.com/1e1feb846042722a8df671de070a32374221e499
Cr-Commit-Position: refs/heads/master@{#434150}

[fdoray, 2016-11-21 22:16:32]

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

[commit-bot: I haz the power, 2016-11-21 22:17:17]

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, 2016-11-21 23:51:51]

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

[commit-bot: I haz the power, 2016-11-21 23:51:52]

Dry run: This issue passed the CQ dry run.

[fdoray, 2016-11-22 13:18:04]

fdoray@chromium.org changed reviewers:
+ dcheng@chromium.org

[fdoray, 2016-11-22 13:18:05]

PTAL

[dcheng, 2016-11-23 02:12:36]

lgtm

[fdoray, 2016-11-23 11:29:37]

The CQ bit was checked by fdoray@chromium.org

[commit-bot: I haz the power, 2016-11-23 11:29:46]

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, 2016-11-23 12:30:02]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1479900577034570,
"parent_rev": "9826dfd5602c2d7c005d8c496ec7c67467265b77", "commit_rev":
"657b522f3f98798d09478c64ac67e63f8d4b8308"}

[commit-bot: I haz the power, 2016-11-23 12:30:26]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-11-23 12:32:43]

Description was changed from

==========
Remove destruction observer from file_path_watcher_win.cc

Now that the FilePathWatcher::~FilePathWatcher() is called on the same
sequence as FilePathWatcher::Watch() (see
https://codereview.chromium.org/2438913003/), the work done in
FilePathWatcherImpl::WillDestroyCurrentMessageLoop() can safely be
moved to FilePathWatcherImpl::Cancel().

BUG=650318
==========

to

==========
Remove destruction observer from file_path_watcher_win.cc

Now that the FilePathWatcher::~FilePathWatcher() is called on the same
sequence as FilePathWatcher::Watch() (see
https://codereview.chromium.org/2438913003/), the work done in
FilePathWatcherImpl::WillDestroyCurrentMessageLoop() can safely be
moved to FilePathWatcherImpl::Cancel().

BUG=650318

Committed: https://crrev.com/1e1feb846042722a8df671de070a32374221e499
Cr-Commit-Position: refs/heads/master@{#434150}
==========

[commit-bot: I haz the power, 2016-11-23 12:32:44]

Patchset 2 (id:??) landed as
https://crrev.com/1e1feb846042722a8df671de070a32374221e499
Cr-Commit-Position: refs/heads/master@{#434150}