Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

With a 10.9 deployment target, the compiler emits
  'gestaltSystemVersionMajor' is deprecated: first deprecated in OS X 10.8
  - Use NSProcessInfo's operatingSystemVersion property instead.

Except, operatingSystemVersion was only added to NSProcessInfo in 10.10.
Use it when it is available, and suppress the deprecation warning
otherwise.

BUG=547071
Committed: https://crrev.com/0ffa1e42503f51e413ef86eaf33dc8d94ef97bea
Cr-Commit-Position: refs/heads/master@{#384419}

[tapted, 2016-03-30 21:34:32]

Description was changed from

==========
Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac


BUG=547071
==========

to

==========
Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

With a 10.9 deployment target, the compiler emits
  'gestaltSystemVersionMajor' is deprecated: first deprecated in OS X 10.8
  - Use NSProcessInfo's operatingSystemVersion property instead.

Except, operatingSystemVersion was only added to NSProcessInfo in 10.10.
Use it when it is available, and suppress the deprecation warning
otherwise.

BUG=547071
==========

[tapted, 2016-03-31 13:56:53]

tapted@chromium.org changed reviewers:
+ erikchen@chromium.org, thakis@chromium.org

[tapted, 2016-03-31 13:56:54]

Erik/Nico: WDYT? Maybe there's a neater way..

(cc elly fyi since we were chatting about this)

[Nico, 2016-03-31 13:59:16]

https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm
File base/sys_info_mac.mm (right):

https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm#newcode43
base/sys_info_mac.mm:43: if ([processInfo
respondsToSelector:@selector(operatingSystemVersion)]) {
Didn't someone say yesterday that this silently works on 10.9 too? Is the else
ever executed?

[tapted, 2016-03-31 14:03:15]

On 2016/03/31 13:59:16, Nico wrote:
> https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm
> File base/sys_info_mac.mm (right):
> 
>
https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm#newcode43
> base/sys_info_mac.mm:43: if ([processInfo
> respondsToSelector:@selector(operatingSystemVersion)]) {
> Didn't someone say yesterday that this silently works on 10.9 too? Is the else
> ever executed?

The rumour goes that it was added in 10.9.2 -
https://twitter.com/gparker/status/586107421816332289 via
http://stackoverflow.com/questions/11072804/how-do-i-determine-the-os-version...

So I don't think it's safe to rely on it.

[Nico, 2016-03-31 14:07:41]

lgtm with comment. Thanks!

https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm
File base/sys_info_mac.mm (right):

https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm#newcode50
base/sys_info_mac.mm:50: #pragma clang diagnostic push
Cool, can you add a comment here explaining why it's ok to call the old thing
here, that this will only run on 10.9 prior to 10.9.2, can be removed when we
stop supporting that, etc? I want every -Wdeprecated-declarations suppression to
have a very good reason for why it's there as a comment. (This here has a good
reason, it just needs a comment explaining it :-) )

[tapted, 2016-03-31 18:07:40]

https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm
File base/sys_info_mac.mm (right):

https://codereview.chromium.org/1842213002/diff/1/base/sys_info_mac.mm#newcode50
base/sys_info_mac.mm:50: #pragma clang diagnostic push
On 2016/03/31 14:07:41, Nico wrote:
> Cool, can you add a comment here explaining why it's ok to call the old thing
> here, that this will only run on 10.9 prior to 10.9.2, can be removed when we
> stop supporting that, etc? I want every -Wdeprecated-declarations suppression
to
> have a very good reason for why it's there as a comment. (This here has a good
> reason, it just needs a comment explaining it :-) )

Done. Added:

    // -[NSProcessInfo operatingSystemVersion] is documented available in 10.10.
    // It's also available via a private API since 10.9.2. For the remaining
    // cases in 10.9, rely on ::Gestalt(..). This can be removed once 10.9 is no
    // longer supported. Gestalt was deprecated in 10.8, so suppress the
    // deprecation warning.

[Nico, 2016-03-31 19:42:19]

lgtm, thanks

https://codereview.chromium.org/1842213002/diff/20001/base/sys_info_mac.mm
File base/sys_info_mac.mm (right):

https://codereview.chromium.org/1842213002/diff/20001/base/sys_info_mac.mm#ne...
base/sys_info_mac.mm:51: // cases in 10.9, rely on ::Gestalt(..). This can be
removed once 10.9 is no
Maybe replace last sentence with "Since this code is only needed for 10.9.0 and
10.9.1 and uses the recommended replacement thereafter, suppress the warning for
this fallback case?"

[tapted, 2016-03-31 20:44:23]

https://codereview.chromium.org/1842213002/diff/20001/base/sys_info_mac.mm
File base/sys_info_mac.mm (right):

https://codereview.chromium.org/1842213002/diff/20001/base/sys_info_mac.mm#ne...
base/sys_info_mac.mm:51: // cases in 10.9, rely on ::Gestalt(..). This can be
removed once 10.9 is no
On 2016/03/31 19:42:19, Nico wrote:
> Maybe replace last sentence with "Since this code is only needed for 10.9.0
and
> 10.9.1 and uses the recommended replacement thereafter, suppress the warning
for
> this fallback case?"

Done.

[tapted, 2016-03-31 20:47:55]

The CQ bit was checked by tapted@chromium.org

[tapted, 2016-03-31 20:47:55]

The patchset sent to the CQ was uploaded after l-g-t-m from thakis@chromium.org
Link to the patchset: https://codereview.chromium.org/1842213002/#ps40001
(title: "clearer")

[commit-bot: I haz the power, 2016-03-31 20:49:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1842213002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1842213002/40001

[commit-bot: I haz the power, 2016-03-31 22:28:39]

Description was changed from

==========
Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

With a 10.9 deployment target, the compiler emits
  'gestaltSystemVersionMajor' is deprecated: first deprecated in OS X 10.8
  - Use NSProcessInfo's operatingSystemVersion property instead.

Except, operatingSystemVersion was only added to NSProcessInfo in 10.10.
Use it when it is available, and suppress the deprecation warning
otherwise.

BUG=547071
==========

to

==========
Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

With a 10.9 deployment target, the compiler emits
  'gestaltSystemVersionMajor' is deprecated: first deprecated in OS X 10.8
  - Use NSProcessInfo's operatingSystemVersion property instead.

Except, operatingSystemVersion was only added to NSProcessInfo in 10.10.
Use it when it is available, and suppress the deprecation warning
otherwise.

BUG=547071
==========

[commit-bot: I haz the power, 2016-03-31 22:28:40]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-03-31 22:30:30]

Description was changed from

==========
Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

With a 10.9 deployment target, the compiler emits
  'gestaltSystemVersionMajor' is deprecated: first deprecated in OS X 10.8
  - Use NSProcessInfo's operatingSystemVersion property instead.

Except, operatingSystemVersion was only added to NSProcessInfo in 10.10.
Use it when it is available, and suppress the deprecation warning
otherwise.

BUG=547071
==========

to

==========
Mac: Avoid deprecated use of ::Gestalt() in base/sys_info_mac

With a 10.9 deployment target, the compiler emits
  'gestaltSystemVersionMajor' is deprecated: first deprecated in OS X 10.8
  - Use NSProcessInfo's operatingSystemVersion property instead.

Except, operatingSystemVersion was only added to NSProcessInfo in 10.10.
Use it when it is available, and suppress the deprecation warning
otherwise.

BUG=547071

Committed: https://crrev.com/0ffa1e42503f51e413ef86eaf33dc8d94ef97bea
Cr-Commit-Position: refs/heads/master@{#384419}
==========

[commit-bot: I haz the power, 2016-03-31 22:30:31]

Patchset 3 (id:??) landed as
https://crrev.com/0ffa1e42503f51e413ef86eaf33dc8d94ef97bea
Cr-Commit-Position: refs/heads/master@{#384419}