Revert of Remove the 'gyp_config' concept from MB.

Revert of Remove the 'gyp_config' concept from MB. (patchset #2 id:20001 of https://codereview.chromium.org/1348463002/ )

Reason for revert:
Looks like the output_dir part of this is wrong: ...

http://build.chromium.org/p/chromium.perf/builders/Win%20x64%20Builder/builds/17237/steps/generate_build_files/logs/stdio

Original issue's description:
> Remove the 'gyp_config' concept from MB.
>
> Previously MB would try to ensure that the build directory
> passed to it matched the expected gyp configuration for the bot
> (i.e. that we would not pass "//out/Debug" as a path for a
> release bot).
>
> Making this work correctly was awkward for the Win x64 bots
> (which use Release_x64 instead of Release), and it's not clear
> that this check would ever actually catch a real problem.
>
> So, this patch deletes all of the 'gyp_config' logic instead
> and simplifies things.
>
> TBR=scottmg@chromium.org
> BUG=481692
>
> Committed: https://crrev.com/fae80e312dba6818315f4f8f0c3a1d85f6f4f9fb
> Cr-Commit-Position: refs/heads/master@{#349043}

TBR=scottmg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=481692
Committed: https://crrev.com/221341cbdcef0b6efd425ae401ab38a5588c3531
Cr-Commit-Position: refs/heads/master@{#349046}

[Dirk Pranke, 2015-09-16 00:23:44]

Created Revert of Remove the 'gyp_config' concept from MB.

[commit-bot: I haz the power, 2015-09-16 00:24:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1349463003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1349463003/1

[commit-bot: I haz the power, 2015-09-16 00:24:51]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-16 00:25:38]

Patchset 1 (id:??) landed as
https://crrev.com/221341cbdcef0b6efd425ae401ab38a5588c3531
Cr-Commit-Position: refs/heads/master@{#349046}

[commit-bot: I haz the power, 2015-09-23 12:51:42]

Patchset 1 (id:??) landed as
https://crrev.com/221341cbdcef0b6efd425ae401ab38a5588c3531
Cr-Commit-Position: refs/heads/master@{#349046}