Reland of GN: Enable ARC for Mac and iOS in rtc_* templates

Reland of GN: Enable ARC for Mac and iOS in rtc_* templates (patchset #1 id:1 of https://codereview.webrtc.org/2827223003/ )

Reason for revert:
Relanding after fixing ARC issue.

Original issue's description:
> Revert of GN: Enable ARC for Mac and iOS in rtc_* templates (patchset #3 id:40001 of https://codereview.webrtc.org/2781713004/ )
> 
> Reason for revert:
> Breaks mac build
> 
> Original issue's description:
> > GN: Enable ARC for Mac and iOS in rtc_* templates
> > 
> > Remove all uses of retain/release and NSAutoreleasePool.
> > 
> > This makes transformation to Bazel easier.
> > 
> > This CL subsumes https://codereview.webrtc.org/2778163002 and depends on https://codereview.webrtc.org/2784483002/
> > 
> > BUG=webrtc:6412
> > 
> > Review-Url: https://codereview.webrtc.org/2781713004
> > Cr-Commit-Position: refs/heads/master@{#17780}
> > Committed: https://chromium.googlesource.com/external/webrtc/+/6bda02b51dc00401d2a0d04be996ed10e5acac47
> 
> TBR=kjellander@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6412
> 
> Review-Url: https://codereview.webrtc.org/2827223003
> Cr-Commit-Position: refs/heads/master@{#17784}
> Committed: https://chromium.googlesource.com/external/webrtc/+/7c8786ae8f2d8481f74b0ab16eb91a8101fe51dc

TBR=kjellander@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6412
Review-Url: https://codereview.webrtc.org/2834273002
Cr-Commit-Position: refs/heads/master@{#17836}
Committed: https://chromium.googlesource.com/external/webrtc/+/c097710cce7b90ff590f98faeb553d59695a0b17

[kthelgason, 2017-04-22 19:27:45]

Created Reland of GN: Enable ARC for Mac and iOS in rtc_* templates

[kthelgason, 2017-04-22 19:40:07]

The CQ bit was checked by kthelgason@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-22 19:40:14]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-04-22 19:56:34]

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

[commit-bot: I haz the power, 2017-04-22 19:56:35]

Dry run: This issue passed the CQ dry run.

[magjed_webrtc, 2017-04-22 20:42:50]

lgtm

[kjellander_webrtc, 2017-04-24 04:44:09]

lgtm, although it would be useful with a link to or example of what kind of
error originally triggered the revert (that this is fixing).

[kthelgason, 2017-04-24 07:38:25]

On 2017/04/24 04:44:09, kjellander_webrtc wrote:
> lgtm, although it would be useful with a link to or example of what kind of
> error originally triggered the revert (that this is fixing).

Thanks Henrik, that's absolutely valid. Here is an example build failure[1].
The issue was that the RTCPeerConnectionFactory was being released under ARC,
previously it would just leak. This caused the destruction of threads that the
factory owns. Some tasks were still running on the threads that had been
reclaimed and were causing a segmentation violation.


[1]:
https://chromium-swarm.appspot.com/task?id=35a3603c3d432610&refresh=10&show_r...

[kthelgason, 2017-04-24 07:38:37]

The CQ bit was checked by kthelgason@webrtc.org

[commit-bot: I haz the power, 2017-04-24 07:38:44]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-04-24 07:57:17]

CQ is committing da patch.

Bot data: {"patchset_id": 190001, "attempt_start_ts": 1493019517591790,
"parent_rev": "0f109beb3830e1dd690dcf13fcfbcd5327af24f6", "commit_rev":
"c097710cce7b90ff590f98faeb553d59695a0b17"}

[commit-bot: I haz the power, 2017-04-24 07:57:22]

Description was changed from

==========
Reland of GN: Enable ARC for Mac and iOS in rtc_* templates (patchset #1 id:1 of
https://codereview.webrtc.org/2827223003/ )

Reason for revert:
Relanding after fixing ARC issue.

Original issue's description:
> Revert of GN: Enable ARC for Mac and iOS in rtc_* templates (patchset #3
id:40001 of https://codereview.webrtc.org/2781713004/ )
> 
> Reason for revert:
> Breaks mac build
> 
> Original issue's description:
> > GN: Enable ARC for Mac and iOS in rtc_* templates
> > 
> > Remove all uses of retain/release and NSAutoreleasePool.
> > 
> > This makes transformation to Bazel easier.
> > 
> > This CL subsumes https://codereview.webrtc.org/2778163002 and depends on
https://codereview.webrtc.org/2784483002/
> > 
> > BUG=webrtc:6412
> > 
> > Review-Url: https://codereview.webrtc.org/2781713004
> > Cr-Commit-Position: refs/heads/master@{#17780}
> > Committed:
https://chromium.googlesource.com/external/webrtc/+/6bda02b51dc00401d2a0d04be...
> 
> TBR=kjellander@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6412
> 
> Review-Url: https://codereview.webrtc.org/2827223003
> Cr-Commit-Position: refs/heads/master@{#17784}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/7c8786ae8f2d8481f74b0ab16...

TBR=kjellander@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6412
==========

to

==========
Reland of GN: Enable ARC for Mac and iOS in rtc_* templates (patchset #1 id:1 of
https://codereview.webrtc.org/2827223003/ )

Reason for revert:
Relanding after fixing ARC issue.

Original issue's description:
> Revert of GN: Enable ARC for Mac and iOS in rtc_* templates (patchset #3
id:40001 of https://codereview.webrtc.org/2781713004/ )
> 
> Reason for revert:
> Breaks mac build
> 
> Original issue's description:
> > GN: Enable ARC for Mac and iOS in rtc_* templates
> > 
> > Remove all uses of retain/release and NSAutoreleasePool.
> > 
> > This makes transformation to Bazel easier.
> > 
> > This CL subsumes https://codereview.webrtc.org/2778163002 and depends on
https://codereview.webrtc.org/2784483002/
> > 
> > BUG=webrtc:6412
> > 
> > Review-Url: https://codereview.webrtc.org/2781713004
> > Cr-Commit-Position: refs/heads/master@{#17780}
> > Committed:
https://chromium.googlesource.com/external/webrtc/+/6bda02b51dc00401d2a0d04be...
> 
> TBR=kjellander@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:6412
> 
> Review-Url: https://codereview.webrtc.org/2827223003
> Cr-Commit-Position: refs/heads/master@{#17784}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/7c8786ae8f2d8481f74b0ab16...

TBR=kjellander@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:6412

Review-Url: https://codereview.webrtc.org/2834273002
Cr-Commit-Position: refs/heads/master@{#17836}
Committed:
https://chromium.googlesource.com/external/webrtc/+/c097710cce7b90ff590f98fae...
==========

[commit-bot: I haz the power, 2017-04-24 07:57:23]

Committed patchset #2 (id:190001) as
https://chromium.googlesource.com/external/webrtc/+/c097710cce7b90ff590f98fae...