Download or update Mac toolchain for pdfium

Download or update Mac toolchain for pdfium

Add Mac toolchain update logic to check whether toolchain should be
downloaded. For googlers, it should be downloaded by default. This fix
the current sdk directory couldn't be found problem.

For googlers who want to opt out of using toolchain, set "use_system_xcode
= true" in gn config.

Committed: https://pdfium.googlesource.com/pdfium/+/9053f19d78b6215570029d896c1d62bbb0ce5f7d

[Wei Li, 2016-11-18 20:49:54]

Description was changed from

==========
Download Mac toolchain if needed

Add Mac toolchain update logic to check whether toolchain should be
downloaded. For googlers, it should be downloaded by default. This fix
the current sdk directory couldn't be found problem.

For googlers who want to opt out of using toolchain, set "use_system_xcode
= true" in gn config.
==========

to

==========
Download or update Mac toolchain for pdfium

Add Mac toolchain update logic to check whether toolchain should be
downloaded. For googlers, it should be downloaded by default. This fix
the current sdk directory couldn't be found problem.

For googlers who want to opt out of using toolchain, set "use_system_xcode
= true" in gn config.
==========

[Wei Li, 2016-11-18 20:50:27]

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

[commit-bot: I haz the power, 2016-11-18 20:50:32]

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, 2016-11-18 21:23:52]

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

[commit-bot: I haz the power, 2016-11-18 21:23:54]

Dry run: This issue passed the CQ dry run.

[Wei Li, 2016-11-18 21:24:40]

weili@chromium.org changed reviewers:
+ dsinclair@chromium.org, thestig@chromium.org

[Wei Li, 2016-11-18 21:24:40]

pls review, thanks

[Lei Zhang, 2016-11-18 22:01:12]

lgtm

Works for me.

[Wei Li, 2016-11-18 22:03:32]

The CQ bit was checked by weili@chromium.org

[commit-bot: I haz the power, 2016-11-18 22:03:36]

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, 2016-11-18 22:03:51]

Description was changed from

==========
Download or update Mac toolchain for pdfium

Add Mac toolchain update logic to check whether toolchain should be
downloaded. For googlers, it should be downloaded by default. This fix
the current sdk directory couldn't be found problem.

For googlers who want to opt out of using toolchain, set "use_system_xcode
= true" in gn config.
==========

to

==========
Download or update Mac toolchain for pdfium

Add Mac toolchain update logic to check whether toolchain should be
downloaded. For googlers, it should be downloaded by default. This fix
the current sdk directory couldn't be found problem.

For googlers who want to opt out of using toolchain, set "use_system_xcode
= true" in gn config.

Committed:
https://pdfium.googlesource.com/pdfium/+/9053f19d78b6215570029d896c1d62bbb0ce...
==========

[commit-bot: I haz the power, 2016-11-18 22:03:52]

Committed patchset #1 (id:1) as
https://pdfium.googlesource.com/pdfium/+/9053f19d78b6215570029d896c1d62bbb0ce...