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

chrome/browser/sync/invalidations/invalidator_storage.cc

 // 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.
 
 #include "chrome/browser/sync/invalidations/invalidator_storage.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
@@ skipping 98 matching lines @@
     return;
   }
   max_versions[id] = max_version;
 
   base::ListValue max_versions_list;
   SerializeToList(max_versions, &max_versions_list);
   pref_service_->Set(prefs::kInvalidatorMaxInvalidationVersions,
                      max_versions_list);
 }
 
+void InvalidatorStorage::Forget(const invalidation::ObjectId& id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  CHECK(pref_service_);
+  InvalidationVersionMap max_versions = GetAllMaxVersions();
+  max_versions.erase(id);
+
+  base::ListValue max_versions_list;
+  SerializeToList(max_versions, &max_versions_list);
+  pref_service_->Set(prefs::kInvalidatorMaxInvalidationVersions,
+                     max_versions_list);
+}
+
 // static
 void InvalidatorStorage::DeserializeFromList(
     const base::ListValue& max_versions_list,
     InvalidationVersionMap* max_versions_map) {
   max_versions_map->clear();
   for (size_t i = 0; i < max_versions_list.GetSize(); ++i) {
     const DictionaryValue* value = NULL;
     if (!max_versions_list.GetDictionary(i, &value)) {
       DLOG(WARNING) << "Unable to deserialize entry " << i;
       continue;
@@ skipping 98 matching lines @@
                            utf8_state);
 }
 
 void InvalidatorStorage::Clear() {
   DCHECK(thread_checker_.CalledOnValidThread());
   pref_service_->ClearPref(prefs::kInvalidatorMaxInvalidationVersions);
   pref_service_->ClearPref(prefs::kInvalidatorInvalidationState);
 }
 
 }  // namespace browser_sync