Remove default initializtion of BirthPlace in Tracked.

Remove default initializtion of BirthPlace in Tracked.

Previously, MessageLoop::PostTask set the BirthPlace of the Task object
(subclass of Tracked), which would decrement the counter for the
Location("NoFunctionName", "NeedToSetBirthPlace", -1) Birth, and replace
it with a more appropriate Location provided by the FROM_HERE argument.

With the MessageLoop restructuring in r82300, tracking of Births is moved
up from the Task object into the MessageLoop::PendingTask structure. The
side-effect is that the default birth is never decremented, and we double
count each task's creation.

This default Birth is effectively a count of "tasks that were created, but
not posted" without a stored reference to location, so removing it is
the simplest fix to the double counting.

BUG=none
TEST=about:tasks looks sane.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=90290

[jar (doing other things), 2011-05-18 20:46:08]

LGTM... with additional delete below.

Thanks!

http://codereview.chromium.org/7029038/diff/1/base/tracked.cc
File base/tracked.cc (left):

http://codereview.chromium.org/7029038/diff/1/base/tracked.cc#oldcode82
base/tracked.cc:82: SetBirthPlace(Location("NoFunctionName",
"NeedToSetBirthPlace", -1));
Line 80 has no side effects... so it too can go.

[awong, 2011-06-23 21:42:46]

Darin, can you give a OWNERS stamp?

[darin (slow to review), 2011-06-23 23:10:17]

LGTM

[jar (doing other things), 2011-06-24 02:22:22]

LGTM