[Mac] Fix race condition in memory pressure level reporting.

[Mac] Fix race condition in memory pressure level reporting.

The change in https://codereview.chromium.org/2743253006 stops the Mac
memory pressure monitor from checking the current pressure level
directly on each call to GetCurrentPressureLevel(). However, if the OS
sends a pressure change notification, callers of
GetCurrentPressureLevel() may receive the old pressure level. This cl
fixes the race condition by forcing an internal pressure level update
upon receiving a pressure level change notification from the OS.

R=brettw@chromium.org,mark@chromium.org
BUG=720924
Review-Url: https://codereview.chromium.org/2877573002
Cr-Commit-Position: refs/heads/master@{#472171}
Committed: https://chromium.googlesource.com/chromium/src/+/fb11bbe1e11b29ad870bdf5a940847dda841f542

[shrike, 2017-05-10 21:32:35]

PTAL - I tested before and after using the memory_pressure utility, so I believe
this fixes the race condition.

[brettw, 2017-05-11 16:54:42]

lgtm

[shrike, 2017-05-11 18:37:06]

Description was changed from

==========
[Mac] Fix race condition in memory pressure level reporting.

The change in https://codereview.chromium.org/2743253006 stops the Mac
memory pressure monitor from checking the current pressure level
directly on each call to GetCurrentPressureLevel(). However, if the OS
sends a pressure change notification, callers of
GetCurrentPressureLevel() may receive the old pressure level. This cl
fixes the race condition by forcing an internal pressure level update
upon receiving a pressure level change notification from the OS.

R=brettw@chromium.org
BUG=720924
==========

to

==========
[Mac] Fix race condition in memory pressure level reporting.

The change in https://codereview.chromium.org/2743253006 stops the Mac
memory pressure monitor from checking the current pressure level
directly on each call to GetCurrentPressureLevel(). However, if the OS
sends a pressure change notification, callers of
GetCurrentPressureLevel() may receive the old pressure level. This cl
fixes the race condition by forcing an internal pressure level update
upon receiving a pressure level change notification from the OS.

R=brettw@chromium.org,mark@chromium.org
BUG=720924
==========

[shrike, 2017-05-11 18:37:06]

shrike@chromium.org changed reviewers:
+ mark@chromium.org

[shrike, 2017-05-11 18:37:27]

mark@ - requesting owners approval

[shrike, 2017-05-16 16:28:37]

On 2017/05/11 18:37:27, shrike wrote:
> mark@ - requesting owners approval

mark@ - gentle ping

[Mark Mentovai, 2017-05-16 17:11:07]

LGTM

[shrike, 2017-05-16 17:29:27]

The CQ bit was checked by shrike@chromium.org

[commit-bot: I haz the power, 2017-05-16 17:30:14]

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, 2017-05-16 18:30:32]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1494955767848580, "parent_rev":
"80101fbdaea7992de9cd435162351b85df4a5d40", "commit_rev":
"fb11bbe1e11b29ad870bdf5a940847dda841f542"}

[commit-bot: I haz the power, 2017-05-16 18:30:42]

Description was changed from

==========
[Mac] Fix race condition in memory pressure level reporting.

The change in https://codereview.chromium.org/2743253006 stops the Mac
memory pressure monitor from checking the current pressure level
directly on each call to GetCurrentPressureLevel(). However, if the OS
sends a pressure change notification, callers of
GetCurrentPressureLevel() may receive the old pressure level. This cl
fixes the race condition by forcing an internal pressure level update
upon receiving a pressure level change notification from the OS.

R=brettw@chromium.org,mark@chromium.org
BUG=720924
==========

to

==========
[Mac] Fix race condition in memory pressure level reporting.

The change in https://codereview.chromium.org/2743253006 stops the Mac
memory pressure monitor from checking the current pressure level
directly on each call to GetCurrentPressureLevel(). However, if the OS
sends a pressure change notification, callers of
GetCurrentPressureLevel() may receive the old pressure level. This cl
fixes the race condition by forcing an internal pressure level update
upon receiving a pressure level change notification from the OS.

R=brettw@chromium.org,mark@chromium.org
BUG=720924

Review-Url: https://codereview.chromium.org/2877573002
Cr-Commit-Position: refs/heads/master@{#472171}
Committed:
https://chromium.googlesource.com/chromium/src/+/fb11bbe1e11b29ad870bdf5a9408...
==========

[commit-bot: I haz the power, 2017-05-16 18:30:43]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/fb11bbe1e11b29ad870bdf5a9408...