Invalidation trickles mega-patch

sync/notifier/invalidation_util.cc

Index: sync/notifier/invalidation_util.cc
diff --git a/sync/notifier/invalidation_util.cc b/sync/notifier/invalidation_util.cc
index 7cc80d299ba2ab9e21e9777eabcb80f8a9c57772..be254fc31770f51db7ddb144f30847feb35fc5e2 100644
--- a/sync/notifier/invalidation_util.cc
+++ b/sync/notifier/invalidation_util.cc
@@ -27,6 +27,25 @@ bool ObjectIdLessThan::operator()(const invalidation::ObjectId& lhs,
          (lhs.source() == rhs.source() && lhs.name() < rhs.name());
 }
 
+bool InvalidationVersionLessThan::operator()(
+    const syncer::Invalidation& a,
+    const syncer::Invalidation& b) const {
+  DCHECK(a.GetObjectId() == b.GetObjectId())
+      << "a: " << ObjectIdToString(a.GetObjectId()) << ", "
+      << "b: " << ObjectIdToString(a.GetObjectId());
+
+  if (a.IsUnknownVersion() && !b.IsUnknownVersion())
+    return true;
+
+  if (!a.IsUnknownVersion() && b.IsUnknownVersion())
+    return false;
+
+  if (a.IsUnknownVersion() && b.IsUnknownVersion())
+    return false;
+
+  return a.GetVersion() < b.GetVersion();
+}
+
 bool RealModelTypeToObjectId(ModelType model_type,
                              invalidation::ObjectId* object_id) {
   std::string notification_type;