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

chrome/browser/sync/invalidations/invalidator_storage.h

 // 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.
 //
 // Wraps PrefService in an InvalidationStateTracker to allow SyncNotifiers
 // to use PrefService as persistence for invalidation state. It is not thread
 // safe, and lives on the UI thread.
 
 #ifndef CHROME_BROWSER_SYNC_INVALIDATIONS_INVALIDATOR_STORAGE_H_
 #define CHROME_BROWSER_SYNC_INVALIDATIONS_INVALIDATOR_STORAGE_H_
@@ skipping 27 matching lines @@
   virtual ~InvalidatorStorage();
 
   // Erases invalidation versions and state stored on disk.
   void Clear();
 
   // InvalidationStateTracker implementation.
   virtual syncer::InvalidationVersionMap GetAllMaxVersions() const
       OVERRIDE;
   virtual void SetMaxVersion(const invalidation::ObjectId& id,
                              int64 max_version) OVERRIDE;
+  virtual void Forget(const syncer::ObjectIdSet& ids) OVERRIDE;
   // TODO(tim): These are not yet used. Bug 124140.
   virtual void SetInvalidationState(const std::string& state) OVERRIDE;
   virtual std::string GetInvalidationState() const OVERRIDE;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest, SerializeEmptyMap);
   FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest,
                            DeserializeFromListOutOfRange);
   FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest,
                            DeserializeFromListInvalidFormat);
@@ skipping 27 matching lines @@
 
   // May be NULL.
   PrefService* const pref_service_;
 
   DISALLOW_COPY_AND_ASSIGN(InvalidatorStorage);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_INVALIDATIONS_INVALIDATOR_STORAGE_H_