Revert of Add support for GYP_GENERATOR_FLAGS out dir setting for landmines

Revert of Add support for GYP_GENERATOR_FLAGS out dir setting for landmines (patchset #3 id:40001 of https://codereview.chromium.org/695753002/)

Reason for revert:
Win8 Release (NVIDIA) and Win8 Debug (NVIDIA) bots are failing to delete temporary files in the hardware_accelerated_feature_tests.

Example failed build:
http://build.chromium.org/p/chromium.gpu/builders/Win8%20Debug%20%28NVIDIA%29/builds/5655

BUG=429663
Original issue's description:
> Add support for GYP_GENERATOR_FLAGS out dir setting for landmines
> 
> BUG=421894
> 
> Committed: https://crrev.com/6bad0d4fad0ee39e993d90eb2ab8050d650efa2b
> Cr-Commit-Position: refs/heads/master@{#302419}

TBR=scottmg@chromium.org,skyostil@google.com,skyostil@chromium.org,oetuaho@nvidia.com
NOTREECHECKS=true
NOTRY=true
BUG=421894

[Geoff Lang, 2014-11-03 14:50:12]

Created Revert of Add support for GYP_GENERATOR_FLAGS out dir setting for
landmines

[commit-bot: I haz the power, 2014-11-03 14:51:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/697123002/1

[commit-bot: I haz the power, 2014-11-03 14:51:09]

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

[commit-bot: I haz the power, 2014-11-03 14:51:10]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[Sami, 2014-11-03 15:52:22]

skyostil@chromium.org changed reviewers:
+ kbr@chromium.org, zmo@chromium.org

[Sami, 2014-11-03 15:58:18]

I'm not sure how Olli's patch could've caused this. The test is failing because
some process is preventing the deletion of temporary files. The code that is
doing the deletion doesn't appear to use landmines.py to find the out directory
as far as I can tell, so it should be deleting the same directory as before.

Ken, Zhenyao, any ideas? Does the bot just need a reboot?

[Geoff Lang, 2014-11-03 16:00:57]

On 2014/11/03 15:58:18, Sami wrote:
> I'm not sure how Olli's patch could've caused this. The test is failing
because
> some process is preventing the deletion of temporary files. The code that is
> doing the deletion doesn't appear to use landmines.py to find the out
directory
> as far as I can tell, so it should be deleting the same directory as before.
> 
> Ken, Zhenyao, any ideas? Does the bot just need a reboot?

Looks like the Win7 bot is now seeing similar issues.  I can try manually
deleting the directories or rebooting the bots to see if it clears up.

[oetuaho-nv, 2014-11-03 16:06:41]

Sorry for the breakage, I couldn't foresee this. If manually restoring the bots
does not work, we could also look for whether some scripts used for the bots set
GYP_GENERATOR_FLAGS to pinpoint the failure?

[Geoff Lang, 2014-11-03 16:42:17]

On 2014/11/03 16:06:41, oetuaho-nv wrote:
> Sorry for the breakage, I couldn't foresee this. If manually restoring the
bots
> does not work, we could also look for whether some scripts used for the bots
set
> GYP_GENERATOR_FLAGS to pinpoint the failure?

Looks like a reboot did the trick.  Release bot is green and I expect the Debug
one to do the same soon.  Closing this revert.