Add a convenience typedef LazyInstance<T>::Leaky to avoid repeating T.

Converted the first 20 or so hits for LeakyLazyInstanceTraits on codesearch to
demonstrate the benefit at callsites.  The real change is base/lazy_instance.h;
everything else is example.

BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/9192024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@118754 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/tracked_objects.h b/base/tracked_objects.h
index a088ee20..b1bf02e 100644
--- a/base/tracked_objects.h
+++ b/base/tracked_objects.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -575,8 +575,7 @@
   // unregistered_thread_data_pool_.  This lock is leaked at shutdown.
   // The lock is very infrequently used, so we can afford to just make a lazy
   // instance and be safe.
-  static base::LazyInstance<base::Lock,
-      base::LeakyLazyInstanceTraits<base::Lock> > list_lock_;
+  static base::LazyInstance<base::Lock>::Leaky list_lock_;
 
   // We set status_ to SHUTDOWN when we shut down the tracking service.
   static Status status_;