Tweaks to ViewManager:

mojo/services/view_manager/view_manager_connection.h

Index: mojo/services/view_manager/view_manager_connection.h
diff --git a/mojo/services/view_manager/view_manager_connection.h b/mojo/services/view_manager/view_manager_connection.h
index 87997d12c45a9ca6fd4dbc5caca62afd14e9f9ed..b3fa8d72b98d588d3503c1c5615e343f1a6bac32 100644
--- a/mojo/services/view_manager/view_manager_connection.h
+++ b/mojo/services/view_manager/view_manager_connection.h
@@ -6,9 +6,11 @@
 #define MOJO_SERVICES_VIEW_MANAGER_VIEW_MANAGER_CONNECTION_H_
 
 #include <set>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/containers/hash_tables.h"
 #include "mojo/public/cpp/shell/service.h"
 #include "mojo/services/public/interfaces/view_manager/view_manager.mojom.h"
 #include "mojo/services/view_manager/ids.h"
@@ -50,21 +52,28 @@ class MOJO_VIEW_MANAGER_EXPORT ViewManagerConnection
   // Returns the View with the specified id.
   View* GetView(const ViewId& id);
 
-  // Notifies the client of a hierarchy change.
-  void NotifyNodeHierarchyChanged(const NodeId& node,
-                                  const NodeId& new_parent,
-                                  const NodeId& old_parent,
-                                  TransportChangeId server_change_id);
-  void NotifyNodeViewReplaced(const NodeId& node,
-                              const ViewId& new_view_id,
-                              const ViewId& old_view_id);
-  void NotifyNodeDeleted(const NodeId& node,
-                         TransportChangeId server_change_id);
-  void NotifyViewDeleted(const ViewId& view);
+  // The following methods are invoked after the corresponding change has been
+  // processed. They do the appropriate bookkeeping and update the client as
+  // necessary.
+  // TODO(sky): convert these to take Node*s.
+  void ProcessNodeHierarchyChanged(const NodeId& node_id,
+                                   const NodeId& new_parent_id,
+                                   const NodeId& old_parent_id,
+                                   TransportChangeId server_change_id,
+                                   bool originated_change);
+  void ProcessNodeViewReplaced(const NodeId& node,
+                               const ViewId& new_view_id,
+                               const ViewId& old_view_id,
+                               bool originated_change);
+  void ProcessNodeDeleted(const NodeId& node,
+                          TransportChangeId server_change_id,
+                          bool originated_change);
+  void ProcessViewDeleted(const ViewId& view, bool originated_change);
 
  private:
   typedef std::map<TransportConnectionSpecificNodeId, Node*> NodeMap;
   typedef std::map<TransportConnectionSpecificViewId, View*> ViewMap;
+  typedef base::hash_set<TransportNodeId> NodeIdSet;
 
   // Deletes a node owned by this connection. Returns true on success. |source|
   // is the connection that originated the change.
@@ -77,6 +86,18 @@ class MOJO_VIEW_MANAGER_EXPORT ViewManagerConnection
   // Sets the view associated with a node.
   bool SetViewImpl(const NodeId& node_id, const ViewId& view_id);
 
+  // If |node| is known (in |known_nodes_|) does nothing. Otherwise adds |node|
+  // to |nodes|, marks |node| as known and recurses.
+  void GetUnknownNodesFrom(Node* node, std::vector<Node*>* nodes);
+
+  // Returns true if notification should be sent of a hierarchy change. If true
+  // is returned, any nodes that need to be sent to the client are added to
+  // |to_send|.
+  bool ShouldNotifyOnHierarchyChange(const NodeId& node_id,
+                                     const NodeId& new_parent_id,
+                                     const NodeId& old_parent_id,
+                                     std::vector<Node*>* to_send);
+
   // Overridden from IViewManager:
   virtual void CreateNode(TransportNodeId transport_node_id,
                           const Callback<void(bool)>& callback) OVERRIDE;
@@ -120,6 +141,9 @@ class MOJO_VIEW_MANAGER_EXPORT ViewManagerConnection
 
   ViewMap view_map_;
 
+  // The set of nodes that has been communicated to the client.
+  NodeIdSet known_nodes_;
+
   DISALLOW_COPY_AND_ASSIGN(ViewManagerConnection);
 };