Convert WaitableEvent::EventCallback to OnceCallback

Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has been cancelled
and copied there.

BUG=554299
TBR=msramek@chromium.org

Review-Url: https://codereview.chromium.org/2801593002
Cr-Commit-Position: refs/heads/master@{#465128}
Committed: https://chromium.googlesource.com/chromium/src/+/130cfd0cd29bdf5edba20601b496749fd954688f

[tzik, 2017-04-05 08:21:37]

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

[commit-bot: I haz the power, 2017-04-05 08:21:45]

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

[tzik, 2017-04-05 08:25:13]

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

[commit-bot: I haz the power, 2017-04-05 08:25:28]

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, 2017-04-05 09:07:12]

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

[commit-bot: I haz the power, 2017-04-05 09:07:13]

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

[tzik, 2017-04-14 08:54:08]

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

[commit-bot: I haz the power, 2017-04-14 08:54:21]

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, 2017-04-14 09:30:27]

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

[commit-bot: I haz the power, 2017-04-14 09:30:28]

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

[tzik, 2017-04-14 17:28:55]

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

[commit-bot: I haz the power, 2017-04-14 17:29:15]

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

[tzik, 2017-04-14 17:31:46]

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

[commit-bot: I haz the power, 2017-04-14 17:31:58]

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

[tzik, 2017-04-14 18:24:34]

Description was changed from

==========
Convert WaitableEvent::EventCallback to OnceCallback

BUG=
==========

to

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=
==========

[tzik, 2017-04-14 18:25:15]

Description was changed from

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=
==========

to

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=554299
==========

[tzik, 2017-04-14 18:26:38]

tzik@chromium.org changed reviewers:
+ dcheng@chromium.org, tsepez@chromium.org

[tzik, 2017-04-14 18:28:11]

tzik@chromium.org changed reviewers:
+ msramek@chromium.org

[tzik, 2017-04-14 18:28:56]

PTAL to:
dcheng: //base
msramek: //chrome/browser/browsing_data
tsepez: //ipc

[Tom Sepez, 2017-04-14 18:49:55]

LGTM, although I can't prove it's 100% safe, hopefully the bots will ...

https://codereview.chromium.org/2801593002/diff/80001/base/synchronization/wa...
File base/synchronization/waitable_event_watcher_posix.cc (right):

https://codereview.chromium.org/2801593002/diff/80001/base/synchronization/wa...
base/synchronization/waitable_event_watcher_posix.cc:64: base::OnceClosure
callback,
Funny, I thought this would have to be a base::OnceClosure&& but I guess it
works ...

[commit-bot: I haz the power, 2017-04-14 19:20:38]

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

[commit-bot: I haz the power, 2017-04-14 19:20:39]

Dry run: This issue passed the CQ dry run.

[dcheng, 2017-04-14 21:56:59]

https://codereview.chromium.org/2801593002/diff/80001/base/message_loop/messa...
File base/message_loop/message_pump_libevent_unittest.cc (right):

https://codereview.chromium.org/2801593002/diff/80001/base/message_loop/messa...
base/message_loop/message_pump_libevent_unittest.cc:264:
Unretained(watcher.get()), &event, std::move(write_fd_task)));
Nit: #include <utility>

https://codereview.chromium.org/2801593002/diff/80001/base/synchronization/wa...
File base/synchronization/waitable_event_watcher_posix.cc (right):

https://codereview.chromium.org/2801593002/diff/80001/base/synchronization/wa...
base/synchronization/waitable_event_watcher_posix.cc:64: base::OnceClosure
callback,
On 2017/04/14 18:49:55, Tom Sepez wrote:
> Funny, I thought this would have to be a base::OnceClosure&& but I guess it
> works ...

In Google/Chromium, move-only types are passed by value (for anything that's not
a move constructor/assignment operator). This works because the callsites have
to turn the parameter into an rvalue with std::move(), so this invokes the move
constructor when calling the function.

https://codereview.chromium.org/2801593002/diff/80001/ipc/ipc_sync_channel.cc
File ipc/ipc_sync_channel.cc (right):

https://codereview.chromium.org/2801593002/diff/80001/ipc/ipc_sync_channel.cc...
ipc/ipc_sync_channel.cc:114: base::Unretained(this)));
Out of curiosity, why do we need this intermediate OnceCallback? It seems like
we could just std::move(callback_) here.

[tzik, 2017-04-17 08:27:45]

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

[commit-bot: I haz the power, 2017-04-17 08:27:58]

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

[tzik, 2017-04-17 08:28:34]

https://codereview.chromium.org/2801593002/diff/80001/base/message_loop/messa...
File base/message_loop/message_pump_libevent_unittest.cc (right):

https://codereview.chromium.org/2801593002/diff/80001/base/message_loop/messa...
base/message_loop/message_pump_libevent_unittest.cc:264:
Unretained(watcher.get()), &event, std::move(write_fd_task)));
On 2017/04/14 21:56:58, dcheng wrote:
> Nit: #include <utility>

Done.

https://codereview.chromium.org/2801593002/diff/80001/ipc/ipc_sync_channel.cc
File ipc/ipc_sync_channel.cc (right):

https://codereview.chromium.org/2801593002/diff/80001/ipc/ipc_sync_channel.cc...
ipc/ipc_sync_channel.cc:114: base::Unretained(this)));
On 2017/04/14 21:56:59, dcheng wrote:
> Out of curiosity, why do we need this intermediate OnceCallback? It seems like
> we could just std::move(callback_) here.

StartWatching/StopWatching may be called more than once by other
NestedSendDoneWatcher instances (as |outer_state_| of the other instance), so we
can not consume |callback_| here.

[commit-bot: I haz the power, 2017-04-17 09:51:52]

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

[commit-bot: I haz the power, 2017-04-17 09:51:53]

Dry run: This issue passed the CQ dry run.

[dcheng, 2017-04-18 01:06:55]

lgtm

[tzik, 2017-04-18 03:41:23]

Description was changed from

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=554299
==========

to

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=554299
TBR=msramek@chromium.org
==========

[tzik, 2017-04-18 03:45:03]

TBRing msramek for //chrome/browser/browsing_data change, since it's a trivial
change. PTAL later.

[tzik, 2017-04-18 03:45:12]

The CQ bit was checked by tzik@chromium.org

[tzik, 2017-04-18 03:45:13]

The patchset sent to the CQ was uploaded after l-g-t-m from tsepez@chromium.org
Link to the patchset: https://codereview.chromium.org/2801593002/#ps100001
(title: "+#include <utility>")

[commit-bot: I haz the power, 2017-04-18 03:45:35]

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, 2017-04-18 03:49:10]

CQ is committing da patch.

Bot data: {"patchset_id": 100001, "attempt_start_ts": 1492487112839310,
"parent_rev": "b5a0bdbe8b745676efac4996f50c0558bb17b839", "commit_rev":
"130cfd0cd29bdf5edba20601b496749fd954688f"}

[commit-bot: I haz the power, 2017-04-18 03:50:03]

Description was changed from

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=554299
TBR=msramek@chromium.org
==========

to

==========
Convert WaitableEvent::EventCallback to OnceCallback

This CL converts WaitableEvent::EventCallback to base::OnceCallback from
base::Callback.

The non-trivial part is in IPC code. It's called only once anyway, but it has
been cancelled
and copied there.

BUG=554299
TBR=msramek@chromium.org

Review-Url: https://codereview.chromium.org/2801593002
Cr-Commit-Position: refs/heads/master@{#465128}
Committed:
https://chromium.googlesource.com/chromium/src/+/130cfd0cd29bdf5edba20601b496...
==========

[commit-bot: I haz the power, 2017-04-18 03:50:04]

Committed patchset #6 (id:100001) as
https://chromium.googlesource.com/chromium/src/+/130cfd0cd29bdf5edba20601b496...

[msramek, 2017-04-18 09:19:36]

LGTM