Add InvalidationStateTracker::Forget() to erase an entry from storage.

sync/notifier/chrome_invalidation_client.cc

Index: sync/notifier/chrome_invalidation_client.cc
diff --git a/sync/notifier/chrome_invalidation_client.cc b/sync/notifier/chrome_invalidation_client.cc
index 8b9cd4fda6765a1429de57e1e0b30720ac7b4a59..d34dbf6f1c015fe09c74e9d8b7502fba370e71ce 100644
--- a/sync/notifier/chrome_invalidation_client.cc
+++ b/sync/notifier/chrome_invalidation_client.cc
@@ -107,16 +107,15 @@ void ChromeInvalidationClient::RegisterIds(const ObjectIdSet& ids) {
   // working XMPP connection (as observed by us), so check it instead
   // of GetState() (see http://crbug.com/139424).
   if (ticl_state_ == NO_NOTIFICATION_ERROR && registration_manager_.get()) {
-    registration_manager_->SetRegisteredIds(registered_ids_);
+    DoRegistrationUpdate();
   }
-  // TODO(akalin): Clear invalidation versions for unregistered types.
 }
 
 void ChromeInvalidationClient::Ready(
     invalidation::InvalidationClient* client) {
   ticl_state_ = NO_NOTIFICATION_ERROR;
   EmitStateChange();
-  registration_manager_->SetRegisteredIds(registered_ids_);
+  DoRegistrationUpdate();
 }
 
 void ChromeInvalidationClient::Invalidate(
@@ -273,6 +272,18 @@ void ChromeInvalidationClient::WriteState(const std::string& state) {
       FROM_HERE, &InvalidationStateTracker::SetInvalidationState, state);
 }
 
+void ChromeInvalidationClient::DoRegistrationUpdate() {
+  DCHECK(CalledOnValidThread());
+  const ObjectIdSet& unregistered_ids =
+      registration_manager_->SetRegisteredIds(registered_ids_);
+  for (ObjectIdSet::const_iterator it = unregistered_ids.begin();
+       it != unregistered_ids.end();
+       ++it) {
+    invalidation_state_tracker_.Call(

[akalin, 2012/08/02 07:04:30]

you trigger a post on another thread for each ID, each of which rewrites a pref.
 Perhaps Forget() should take a set instead?

+        FROM_HERE, &InvalidationStateTracker::Forget, *it);
+  }
+}
+
 void ChromeInvalidationClient::Stop() {
   DCHECK(CalledOnValidThread());
   if (!invalidation_client_.get()) {