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.

Review URL: http://codereview.chromium.org/7029038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@90290 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 7 insertions, 6 deletions

diff --git a/base/tracked.cc b/base/tracked.cc
index 0a246ae..08c38a7 100644
--- a/base/tracked.cc
+++ b/base/tracked.cc
@@ -107,9 +107,6 @@ void Tracked::ResetBirthTime() {}
 Tracked::Tracked()
     : tracked_births_(NULL),
       tracked_birth_time_(TimeTicks::Now()) {
-  if (!ThreadData::IsActive())
-    return;
-  SetBirthPlace(Location("NoFunctionName", "NeedToSetBirthPlace", -1, NULL));
 }
 
 Tracked::~Tracked() {
diff --git a/base/tracked_objects_unittest.cc b/base/tracked_objects_unittest.cc
index ab615da..e7d07a7 100644
--- a/base/tracked_objects_unittest.cc
+++ b/base/tracked_objects_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -60,10 +60,12 @@ TEST_F(TrackedObjectsTest, TinyStartupShutdown) {
     return;
 
   // Instigate tracking on a single tracked object, or our thread.
+  const Location& location = FROM_HERE;
   NoopTracked tracked;
+  tracked.SetBirthPlace(location);
 
   const ThreadData* data = ThreadData::first();
-  EXPECT_TRUE(data);
+  ASSERT_TRUE(data);
   EXPECT_TRUE(!data->next());
   EXPECT_EQ(data, ThreadData::current());
   ThreadData::BirthMap birth_map;
@@ -76,7 +78,9 @@ TEST_F(TrackedObjectsTest, TinyStartupShutdown) {
 
 
   // Now instigate a birth, and a death.
-  delete new NoopTracked;
+  NoopTracked* new_tracked = new NoopTracked;
+  new_tracked->SetBirthPlace(location);
+  delete new_tracked;
 
   birth_map.clear();
   data->SnapshotBirthMap(&birth_map);