Avoid calling NotificationService::current() unless we have to, to prevent problems during shutdown in atypical cases.We can now be more stringent with the Remove() check that was already in place, since now users _must_ go through NotificationRegistrar to register an observer.

BUG=12560
Review URL: http://codereview.chromium.org/115733

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@16821 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 7 deletions

diff --git a/chrome/common/notification_registrar.cc b/chrome/common/notification_registrar.cc
index 73635b5..ac76202 100644
--- a/chrome/common/notification_registrar.cc
+++ b/chrome/common/notification_registrar.cc
@@ -47,15 +47,11 @@ void NotificationRegistrar::Remove(NotificationObserver* observer,
   Record record = { observer, type, source };
   RecordVector::iterator found = std::find(
       registered_.begin(), registered_.end(), record);
-  if (found != registered_.end()) {
-    registered_.erase(found);
-  } else {
-    // Fall through to passing the removal through to the notification service.
-    // If it really isn't registered, it will also assert and do nothing, but
-    // we might as well catch the case where the class is trying to unregister
-    // for something they registered without going through us.
+  if (found == registered_.end()) {
     NOTREACHED();
+    return;
   }
+  registered_.erase(found);
 
   // This can be NULL if our owner outlives the NotificationService, e.g. if our
   // owner is a Singleton.
@@ -65,6 +61,15 @@ void NotificationRegistrar::Remove(NotificationObserver* observer,
 }
 
 void NotificationRegistrar::RemoveAll() {
+  // Early-exit if no registrations, to avoid calling
+  // NotificationService::current.  If we've constructed an object with a
+  // NotificationRegistrar member, but haven't actually used the notification
+  // service, and we reach prgram exit, then calling current() below could try
+  // to initialize the service's lazy TLS pointer during exit, which throws
+  // wrenches at things.
+  if (registered_.empty())
+    return;
+
   // This can be NULL if our owner outlives the NotificationService, e.g. if our
   // owner is a Singleton.
   NotificationService* service = NotificationService::current();