Map new subtrees when they are attached to the node hierarchy visible to a connection.

mojo/services/view_manager/view_manager_connection.cc

Index: mojo/services/view_manager/view_manager_connection.cc
diff --git a/mojo/services/view_manager/view_manager_connection.cc b/mojo/services/view_manager/view_manager_connection.cc
index cac1ef3ec02fbd1ea22f825cf04bd9429f0a79c9..69f2b77a8becd40aaae39e08e4ef22b6e8f72755 100644
--- a/mojo/services/view_manager/view_manager_connection.cc
+++ b/mojo/services/view_manager/view_manager_connection.cc
@@ -121,12 +121,15 @@ void ViewManagerConnection::ProcessNodeViewReplaced(
     bool originated_change) {
   if (originated_change)
     return;
-  const TransportViewId new_view_id = new_view ?
-      ViewIdToTransportId(new_view->id()) : 0;
-  const TransportViewId old_view_id = old_view ?
-      ViewIdToTransportId(old_view->id()) : 0;
-  client()->OnNodeViewReplaced(NodeIdToTransportId(node->id()),
-                               new_view_id, old_view_id);
+  if (known_nodes_.find(NodeIdToTransportId(node->id())) !=

[sky, 2014/05/16 23:28:22]

nit: use known_nodes_.count > 0 (it's shorter and what I've used throughout the
rest of this file).

+      known_nodes_.end()) {
+    const TransportViewId new_view_id = new_view ?
+        ViewIdToTransportId(new_view->id()) : 0;
+    const TransportViewId old_view_id = old_view ?
+        ViewIdToTransportId(old_view->id()) : 0;
+    client()->OnNodeViewReplaced(NodeIdToTransportId(node->id()),
+                                 new_view_id, old_view_id);
+  }
 }
 
 void ViewManagerConnection::ProcessNodeDeleted(
@@ -264,6 +267,7 @@ void ViewManagerConnection::CreateNode(
     return;
   }
   node_map_[node_id.node_id] = new Node(this, node_id);
+  known_nodes_.insert(transport_node_id);
   callback.Run(true);
 }