Disable building unit_tests.exe on DrMemory builders.

Disable building unit_tests.exe on DrMemory builders.
The "Chromium Windows Builder (DrMemory)" bot runs out of memory when link.exe creates unit_test.exe because DrMemory needs static builds. This change just disables building unit_tests.exe as a better-than-nothing workaround.

BUG=137180
TEST=make the "Chromium Windows Builder (DrMemory)" bot green.
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=146551

[Timur Iskhodzhanov, 2012-07-13 08:21:49]

LGTM as a short-term solution

[commit-bot: I haz the power, 2012-07-13 08:36:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hbono@chromium.org/10736065/1

[commit-bot: I haz the power, 2012-07-13 09:43:08]

Try job failure for 10736065-1 (retry) on linux_rel for step "browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[Timur Iskhodzhanov, 2012-07-13 11:21:15]

Why can't I CQ again?..

[Hironori Bono, 2012-07-13 11:31:53]

Greetings Timur,

Sorry for bothering you. I have landed this change manually so the "Chromium
Windows Builder (DrMemory)" bot can get it as soon as possible.

Regards,

Hironori Bono