Implement features needed for local ack handling in InvalidationStateTracker.

sync/notifier/invalidation_state_tracker.cc

Index: sync/notifier/invalidation_state_tracker.cc
diff --git a/sync/notifier/invalidation_state_tracker.cc b/sync/notifier/invalidation_state_tracker.cc
index 9d21807beada61224cdb5e4f4519c278773a79ba..335f3b2a61db1460d973d155a7d0247c74f47ac1 100644
--- a/sync/notifier/invalidation_state_tracker.cc
+++ b/sync/notifier/invalidation_state_tracker.cc
@@ -6,8 +6,19 @@
 
 namespace syncer {
 
+InvalidationState::InvalidationState()
+    : version(kint64min),
+      expected(AckHandle::InvalidAckHandle()),
+      current(AckHandle::InvalidAckHandle()) {
+}
+
+InvalidationState::~InvalidationState() {
+}
+
 bool operator==(const InvalidationState& lhs, const InvalidationState& rhs) {
-  return lhs.version == rhs.version;
+  return lhs.version == rhs.version &&
+      lhs.expected.Equals(rhs.expected) &&
+      lhs.current.Equals(rhs.current);
 }
 
 }  // namespace syncer