Reland "Remove the 'gyp_config' concept from MB."

Reland "Remove the 'gyp_config' concept from MB."

This re-lands #349043 with some fixes for win32; we weren't consistently
using os.sep everywhere. This patch fixes that and consolidates the code
so that all references to os.sep and os.path.join() happen in the same
places. In addition, this patch updates the unittests to run cleanly on
win32 and test a win32-specific example (to catch the case that broke).

TBR=scottmg@chromium.org
BUG=481692
Committed: https://crrev.com/8c2cfd36d9ddcd4c1d6cc23b8e1dad2cc317e54c
Cr-Commit-Position: refs/heads/master@{#349477}

[Dirk Pranke, 2015-09-17 00:25:29]

Patchset #2 (id:20001) has been deleted

[Dirk Pranke, 2015-09-17 00:25:51]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2015-09-17 00:26:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1348153003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1348153003/40001

[scottmg, 2015-09-17 00:32:02]

Was it only tests that were failing before? Otherwise I don't understand how
self.PathJoin and self.sep help?

[Dirk Pranke, 2015-09-17 00:41:24]

No, there was a real bug (I've commented on the line that was wrong).

https://codereview.chromium.org/1348153003/diff/40001/tools/mb/mb.py
File tools/mb/mb.py (left):

https://codereview.chromium.org/1348153003/diff/40001/tools/mb/mb.py#oldcode595
tools/mb/mb.py:595: output_dir, _, config = rpath.rpartition('/')
this was the problematic line (should've been self.sep or os.sep instead of a
hardcoded forward slash.

[scottmg, 2015-09-17 00:44:15]

Aha, I see. lgtm

[scottmg, 2015-09-17 00:44:41]

(but I said that last time :)

[Dirk Pranke, 2015-09-17 00:50:38]

The CQ bit was unchecked by dpranke@chromium.org

[Dirk Pranke, 2015-09-17 00:50:46]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2015-09-17 00:50:47]

The patchset sent to the CQ was uploaded after l-g-t-m from scottmg@chromium.org
Link to the patchset: https://codereview.chromium.org/1348153003/#ps60001
(title: "fix win32 test on non-win32 platform")

[commit-bot: I haz the power, 2015-09-17 00:51:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1348153003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1348153003/60001

[commit-bot: I haz the power, 2015-09-17 01:36:53]

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

[commit-bot: I haz the power, 2015-09-17 01:36:54]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Dirk Pranke, 2015-09-17 02:09:20]

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

[commit-bot: I haz the power, 2015-09-17 02:09:39]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1348153003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1348153003/60001

[commit-bot: I haz the power, 2015-09-17 02:39:36]

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

[commit-bot: I haz the power, 2015-09-17 02:39:37]

Dry run: This issue passed the CQ dry run.

[Dirk Pranke, 2015-09-17 20:05:11]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2015-09-17 20:06:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1348153003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1348153003/60001

[commit-bot: I haz the power, 2015-09-17 20:12:41]

Committed patchset #3 (id:60001)

[commit-bot: I haz the power, 2015-09-17 20:13:21]

Patchset 3 (id:??) landed as
https://crrev.com/8c2cfd36d9ddcd4c1d6cc23b8e1dad2cc317e54c
Cr-Commit-Position: refs/heads/master@{#349477}