Fix EtwTraceConsumerDataTest fixture.

Fix EtwTraceConsumerDataTest fixture.

BUG=129129
TEST=The unittest no longer fails on trybots.

Committed at http://crrev.com/138352.

[Sigurður Ásgeirsson, 2012-05-22 17:51:42]

PTAL
Mark for owner's approval.
Greg for content. This is a silly mistake that only comes to light when the GUID
in the base fixture happens to be uninitialized to GUID_NULL :/.

[Mark Mentovai, 2012-05-22 17:53:22]

LGTM

[grt (UTC plus 2), 2012-05-22 18:25:25]

lgtm

[commit-bot: I haz the power, 2012-05-22 18:30:29]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/siggi@chromium.org/10407098/1

[commit-bot: I haz the power, 2012-05-22 22:29:00]

Try job failure for 10407098-1 (retry) on win_rel for steps "check_deps,
unit_tests, sync_unit_tests" (clobber build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2012-05-23 06:42:31]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/siggi@chromium.org/10407098/1

[commit-bot: I haz the power, 2012-05-23 06:42:34]

Failed to apply patch for base/win/event_trace_consumer_unittest.cc:
While running patch -p1 --forward --force;
patching file base/win/event_trace_consumer_unittest.cc
Hunk #1 FAILED at 282.
1 out of 1 hunk FAILED -- saving rejects to file
base/win/event_trace_consumer_unittest.cc.rej