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

sync/notifier/fake_invalidation_state_tracker.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 "sync/notifier/fake_invalidation_state_tracker.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace syncer {
 
 const int64 FakeInvalidationStateTracker::kMinVersion = kint64min;
 
 FakeInvalidationStateTracker::FakeInvalidationStateTracker() {}
 
 FakeInvalidationStateTracker::~FakeInvalidationStateTracker() {}
 
+int64 FakeInvalidationStateTracker::GetMaxVersion(
+    const invalidation::ObjectId& id) const {
+  InvalidationVersionMap::const_iterator it = versions_.find(id);
+  return (it == versions_.end()) ? kMinVersion : it->second;
+}
+
 InvalidationVersionMap
 FakeInvalidationStateTracker::GetAllMaxVersions() const {
   return versions_;
 }
 
 void FakeInvalidationStateTracker::SetMaxVersion(
     const invalidation::ObjectId& id, int64 max_version) {
   InvalidationVersionMap::const_iterator it = versions_.find(id);
   if ((it != versions_.end()) && (max_version <= it->second)) {
     ADD_FAILURE();
     return;
   }
   versions_[id] = max_version;
 }
 
-int64 FakeInvalidationStateTracker::GetMaxVersion(
-    const invalidation::ObjectId& id) const {
-  InvalidationVersionMap::const_iterator it = versions_.find(id);
-  return (it == versions_.end()) ? kMinVersion : it->second;
+void FakeInvalidationStateTracker::Forget(const ObjectIdSet& ids) {
+  for (ObjectIdSet::const_iterator it = ids.begin(); it != ids.end(); ++it) {
+    versions_.erase(*it);
+  }
 }
 
 void FakeInvalidationStateTracker::SetInvalidationState(
     const std::string& state) {
   state_ = state;
 }
 
 std::string FakeInvalidationStateTracker::GetInvalidationState() const {
   return state_;
 }
 
 }  // namespace syncer