[GN] Sanitize environment variables when running ninja from Xcode.

[GN] Sanitize environment variables when running ninja from Xcode.

When invoking build script from Xcode, many environment variables
are exported by Xcode based on the project settings. Sanitize the
environment as those variable interact poorly with the hermetic
build (see linked bug for detail of failure more).

BUG=634501
Committed: https://crrev.com/84aac8fc963ba786889000c40bb5c5a7e95b1b3b
Cr-Commit-Position: refs/heads/master@{#435707}

[sdefresne, 2016-12-01 13:04:47]

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

[commit-bot: I haz the power, 2016-12-01 13:04:57]

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

[sdefresne, 2016-12-01 13:05:34]

sdefresne@chromium.org changed reviewers:
+ dpranke@chromium.org

[sdefresne, 2016-12-01 13:05:35]

Please take a look and send to CQ if LGTY.

I've tested that I can successfully build and run app with latest Xcode using
hermetic build on mac and build downstream code on iOS with this patch.

[commit-bot: I haz the power, 2016-12-01 13:14:09]

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

[commit-bot: I haz the power, 2016-12-01 13:14:10]

Dry run: This issue passed the CQ dry run.

[Dirk Pranke, 2016-12-01 20:53:22]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2016-12-01 20:53:22]

lgtm

lgtm. Feel free to address the comments in a follow-up patch.

https://codereview.chromium.org/2544803002/diff/1/tools/gn/xcode_writer.cc
File tools/gn/xcode_writer.cc (right):

https://codereview.chromium.org/2544803002/diff/1/tools/gn/xcode_writer.cc#ne...
tools/gn/xcode_writer.cc:40: {"HOME", true}, {"LANG", true},    {"PATH", true},
nit: weird indentation.

https://codereview.chromium.org/2544803002/diff/1/tools/gn/xcode_writer.cc#ne...
tools/gn/xcode_writer.cc:66: for (size_t i = 0; i <
arraysize(kSafeEnvironmentVariables); ++i) {
Can you replace this with a range-based loop? I.e., `for (const auto& variable:
kSafeEnvironmentVariables)` or some such?

[commit-bot: I haz the power, 2016-12-01 20:54:21]

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, 2016-12-01 20:58:29]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480625602087610, "parent_rev":
"86c00f5adf4502a955e0a3e1de3b3a01b3c6f06e", "commit_rev":
"4211f7e330320920520798f6d2631af6e705f29f"}

[commit-bot: I haz the power, 2016-12-01 20:59:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-01 21:01:32]

Description was changed from

==========
[GN] Sanitize environment variables when running ninja from Xcode.

When invoking build script from Xcode, many environment variables
are exported by Xcode based on the project settings. Sanitize the
environment as those variable interact poorly with the hermetic
build (see linked bug for detail of failure more).

BUG=634501
==========

to

==========
[GN] Sanitize environment variables when running ninja from Xcode.

When invoking build script from Xcode, many environment variables
are exported by Xcode based on the project settings. Sanitize the
environment as those variable interact poorly with the hermetic
build (see linked bug for detail of failure more).

BUG=634501

Committed: https://crrev.com/84aac8fc963ba786889000c40bb5c5a7e95b1b3b
Cr-Commit-Position: refs/heads/master@{#435707}
==========

[commit-bot: I haz the power, 2016-12-01 21:01:33]

Patchset 1 (id:??) landed as
https://crrev.com/84aac8fc963ba786889000c40bb5c5a7e95b1b3b
Cr-Commit-Position: refs/heads/master@{#435707}

[sdefresne, 2016-12-06 14:02:49]

Followup changes addressed with https://codereview.chromium.org/2556743002/