Nukes change_ids from view manager

change_ids are more trouble then they are worth. I'm going to try
something else for resolving conflicts.

BUG=389339
TEST=covered by tests
R=ben@chromium.org

Review URL: https://codereview.chromium.org/397263004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283830 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 186 insertions, 504 deletions

diff --git a/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.cc b/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.cc
index 4a69ff0..76bf054 100644
--- a/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.cc
+++ b/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.cc
@@ -133,10 +133,6 @@ class ViewManagerTransaction {
 
   ViewManagerService* service() { return client_->service_; }
 
-  Id GetAndAdvanceNextServerChangeId() {
-    return client_->next_server_change_id_++;
-  }
-
   // TODO(sky): nuke this and covert all to new one, then rename
   // ActionCompletedCallbackWithErrorCode to ActionCompletedCallback.
   base::Callback<void(bool)> ActionCompletedCallback() {
@@ -246,9 +242,7 @@ class DestroyNodeTransaction : public ViewManagerTransaction {
  private:
   // Overridden from ViewManagerTransaction:
   virtual void DoCommit() OVERRIDE {
-    service()->DeleteNode(node_id_,
-                          GetAndAdvanceNextServerChangeId(),
-                          ActionCompletedCallback());
+    service()->DeleteNode(node_id_, ActionCompletedCallback());
   }
   virtual void DoActionCompleted(bool success) OVERRIDE {
     // TODO(beng): recovery?
@@ -272,10 +266,7 @@ class AddChildTransaction : public ViewManagerTransaction {
  private:
   // Overridden from ViewManagerTransaction:
   virtual void DoCommit() OVERRIDE {
-    service()->AddNode(parent_id_,
-                       child_id_,
-                       GetAndAdvanceNextServerChangeId(),
-                       ActionCompletedCallback());
+    service()->AddNode(parent_id_, child_id_, ActionCompletedCallback());
   }
 
   virtual void DoActionCompleted(bool success) OVERRIDE {
@@ -299,10 +290,7 @@ class RemoveChildTransaction : public ViewManagerTransaction {
  private:
   // Overridden from ViewManagerTransaction:
   virtual void DoCommit() OVERRIDE {
-    service()->RemoveNodeFromParent(
-        child_id_,
-        GetAndAdvanceNextServerChangeId(),
-        ActionCompletedCallback());
+    service()->RemoveNodeFromParent(child_id_, ActionCompletedCallback());
   }
 
   virtual void DoActionCompleted(bool success) OVERRIDE {
@@ -333,7 +321,6 @@ class ReorderNodeTransaction : public ViewManagerTransaction {
     service()->ReorderNode(node_id_,
                            relative_id_,
                            direction_,
-                           GetAndAdvanceNextServerChangeId(),
                            ActionCompletedCallback());
   }
 
@@ -478,7 +465,6 @@ class EmbedTransaction : public ViewManagerTransaction {
  private:
   // Overridden from ViewManagerTransaction:
   virtual void DoCommit() OVERRIDE {
-    GetAndAdvanceNextServerChangeId();
     service()->Embed(url_, node_id_, ActionCompletedCallback());
   }
   virtual void DoActionCompleted(bool success) OVERRIDE {
@@ -542,7 +528,6 @@ ViewManagerClientImpl::ViewManagerClientImpl(ApplicationConnection* connection,
     : connected_(false),
       connection_id_(0),
       next_id_(1),
-      next_server_change_id_(0),
       delegate_(delegate),
       dispatcher_(NULL) {}
 
@@ -733,12 +718,10 @@ void ViewManagerClientImpl::OnConnectionEstablished() {
 void ViewManagerClientImpl::OnViewManagerConnectionEstablished(
     ConnectionSpecificId connection_id,
     const String& creator_url,
-    Id next_server_change_id,
     Array<NodeDataPtr> nodes) {
   connected_ = true;
   connection_id_ = connection_id;
   creator_url_ = TypeConverter<String, std::string>::ConvertFrom(creator_url);
-  next_server_change_id_ = next_server_change_id;
 
   DCHECK(pending_transactions_.empty());
   AddRoot(BuildNodeTree(this, nodes));
@@ -748,11 +731,6 @@ void ViewManagerClientImpl::OnRootAdded(Array<NodeDataPtr> nodes) {
   AddRoot(BuildNodeTree(this, nodes));
 }
 
-void ViewManagerClientImpl::OnServerChangeIdAdvanced(
-    Id next_server_change_id) {
-  next_server_change_id_ = next_server_change_id;
-}
-
 void ViewManagerClientImpl::OnNodeBoundsChanged(Id node_id,
                                                 RectPtr old_bounds,
                                                 RectPtr new_bounds) {
@@ -765,10 +743,7 @@ void ViewManagerClientImpl::OnNodeHierarchyChanged(
     Id node_id,
     Id new_parent_id,
     Id old_parent_id,
-    Id server_change_id,
     mojo::Array<NodeDataPtr> nodes) {
-  next_server_change_id_ = server_change_id + 1;
-
   BuildNodeTree(this, nodes);
 
   Node* new_parent = GetNodeById(new_parent_id);
@@ -782,20 +757,14 @@ void ViewManagerClientImpl::OnNodeHierarchyChanged(
 
 void ViewManagerClientImpl::OnNodeReordered(Id node_id,
                                             Id relative_node_id,
-                                            OrderDirection direction,
-                                            Id server_change_id) {
-  next_server_change_id_ = server_change_id + 1;
-
+                                            OrderDirection direction) {
   Node* node = GetNodeById(node_id);
   Node* relative_node = GetNodeById(relative_node_id);
-  if (node && relative_node) {
+  if (node && relative_node)
     NodePrivate(node).LocalReorder(relative_node, direction);
-  }
 }
 
-void ViewManagerClientImpl::OnNodeDeleted(Id node_id, Id server_change_id) {
-  next_server_change_id_ = server_change_id + 1;
-
+void ViewManagerClientImpl::OnNodeDeleted(Id node_id) {
   Node* node = GetNodeById(node_id);
   if (node)
     NodePrivate(node).LocalDestroy();
diff --git a/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.h b/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.h
index 8383648..69715b0 100644
--- a/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.h
+++ b/mojo/services/public/cpp/view_manager/lib/view_manager_client_impl.h
@@ -102,23 +102,19 @@ class ViewManagerClientImpl : public ViewManager,
   virtual void OnViewManagerConnectionEstablished(
       ConnectionSpecificId connection_id,
       const String& creator_url,
-      Id next_server_change_id,
       Array<NodeDataPtr> nodes) OVERRIDE;
   virtual void OnRootAdded(Array<NodeDataPtr> nodes) OVERRIDE;
-  virtual void OnServerChangeIdAdvanced(Id next_server_change_id) OVERRIDE;
   virtual void OnNodeBoundsChanged(Id node_id,
                                    RectPtr old_bounds,
                                    RectPtr new_bounds) OVERRIDE;
   virtual void OnNodeHierarchyChanged(Id node_id,
                                       Id new_parent_id,
                                       Id old_parent_id,
-                                      Id server_change_id,
                                       Array<NodeDataPtr> nodes) OVERRIDE;
   virtual void OnNodeReordered(Id node_id,
                                Id relative_node_id,
-                               OrderDirection direction,
-                               Id server_change_id) OVERRIDE;
-  virtual void OnNodeDeleted(Id node_id, Id server_change_id) OVERRIDE;
+                               OrderDirection direction) OVERRIDE;
+  virtual void OnNodeDeleted(Id node_id) OVERRIDE;
   virtual void OnNodeViewReplaced(Id node,
                                   Id new_view_id,
                                   Id old_view_id) OVERRIDE;
@@ -143,7 +139,6 @@ class ViewManagerClientImpl : public ViewManager,
   bool connected_;
   ConnectionSpecificId connection_id_;
   ConnectionSpecificId next_id_;
-  Id next_server_change_id_;
 
   std::string creator_url_;
 
diff --git a/mojo/services/public/interfaces/view_manager/view_manager.mojom b/mojo/services/public/interfaces/view_manager/view_manager.mojom
index e65cc6c..caf57a9 100644
--- a/mojo/services/public/interfaces/view_manager/view_manager.mojom
+++ b/mojo/services/public/interfaces/view_manager/view_manager.mojom
@@ -20,7 +20,6 @@ enum ErrorCode {
   NONE,
   VALUE_IN_USE,
   ILLEGAL_ARGUMENT,
-  UNEXPECTED_CHANGE_ID,
 };
 
 // ViewManagerInitService is responsible for launching the client that controls
@@ -30,12 +29,6 @@ interface ViewManagerInitService {
   EmbedRoot(string url) => (bool success);
 };
 
-// Functions that mutate the hierarchy take a change id. This is an ever
-// increasing integer used to identify the change. Every hierarchy change
-// increases this value. The server only accepts changes where the supplied
-// |server_change_id| matches the expected next value. This ensures changes are
-// made in a well defined order.
-//
 // Nodes and Views are identified by a uint32. The upper 16 bits are the
 // connection id, and the lower 16 the id assigned by the client.
 //
@@ -55,7 +48,7 @@ interface ViewManagerService {
   // Deletes a node. This does not recurse. No hierarchy change notifications
   // are sent as a result of this. Only the connection that created the node can
   // delete it.
-  DeleteNode(uint32 node_id, uint32 change_id) => (bool success);
+  DeleteNode(uint32 node_id) => (bool success);
 
   // Sets the specified bounds of the specified node.
   SetNodeBounds(uint32 node_id, mojo.Rect bounds) => (bool success);
@@ -65,30 +58,25 @@ interface ViewManagerService {
   // any of their roots.
   SetNodeVisibility(uint32 node_id, bool visible) => (bool success);
 
-  // Reparents a node. See description above class for details of |change_id|.
+  // Reparents a node.
   // This fails for any of the following reasons:
-  // . |server_change_id| is not the expected id.
   // . |parent| or |child| does not identify a valid node.
   // . |child| is an ancestor of |parent|.
   // . |child| is already a child of |parent|.
   //
   // This may result in a connection getting OnNodeDeleted(). See
   // RemoveNodeFromParent for details.
-  AddNode(uint32 parent,
-          uint32 child,
-          uint32 server_change_id) => (bool success);
+  AddNode(uint32 parent, uint32 child) => (bool success);
 
-  // Removes a view from its current parent. See description above class for
-  // details of |change_id|. This fails if the node is not valid,
-  // |server_change_id| doesn't match, or the node already has no parent.
+  // Removes a view from its current parent. This fails if the node is not
+  // valid, |server_change_id| doesn't match, or the node already has no parent.
   //
   // Removing a node from a parent may result in OnNodeDeleted() being sent to
   // other connections. For example, connection A has nodes 1 and 2, with 2 a
   // child of 1. Connection B has a root 1. If 2 is removed from 1 then B gets
   // OnNodeDeleted(). This is done as node 2 is effectively no longer visible to
   // connection B.
-  RemoveNodeFromParent(uint32 node_id,
-                       uint32 server_change_id) => (bool success);
+  RemoveNodeFromParent(uint32 node_id) => (bool success);
 
   // Reorders a node in its parent, relative to |relative_node_id| according to
   // |direction|.
@@ -96,8 +84,7 @@ interface ViewManagerService {
   // children.
   ReorderNode(uint32 node_id,
               uint32 relative_node_id,
-              OrderDirection direction,
-              uint32 server_change_id) => (bool success);
+              OrderDirection direction) => (bool success);
 
   // Returns the nodes comprising the tree starting at |node_id|. |node_id| is
   // the first result in the return value, unless |node_id| is invalid, in which
@@ -155,26 +142,16 @@ interface ViewManagerService {
 [Client=ViewManagerService]
 interface ViewManagerClient {
   // Invoked once the connection has been established. |connection_id| is the id
-  // that uniquely identifies this connection. |next_server_change_id| is the
-  // id of the next change the server is expecting. |nodes| are the nodes
-  // parented to the root.
+  // that uniquely identifies this connection. |nodes| are the nodes parented to
+  // the root.
   OnViewManagerConnectionEstablished(uint16 connection_id,
                                      string creator_url,
-                                     uint32 next_server_change_id,
                                      NodeData[] nodes);
 
   // See description of ViewManagerService::Embed() for details as to when
   // this is invoked.
   OnRootAdded(NodeData[] nodes);
 
-  // This is sent to clients when a change is made to the server that results
-  // in the |server_change_id| changing but the client isn't notified. This is
-  // not sent if the client receives a callback giving a new
-  // |server_change_id|. For example, if a client 1 changes the hierarchy in
-  // some way but client 2 isn't notified of the change, then client 2 gets
-  // OnServerChangeIdAdvanced().
-  OnServerChangeIdAdvanced(uint32 next_server_change_id);
-
   // Invoked when a node's bounds have changed.
   OnNodeBoundsChanged(uint32 node, mojo.Rect old_bounds, mojo.Rect new_bounds);
 
@@ -187,17 +164,15 @@ interface ViewManagerClient {
   OnNodeHierarchyChanged(uint32 node,
                          uint32 new_parent,
                          uint32 old_parent,
-                         uint32 server_change_id,
                          NodeData[] nodes);
 
   // Invoked when the order of nodes within a parent changes.
   OnNodeReordered(uint32 node_id,
                   uint32 relative_node_id,
-                  OrderDirection direction,
-                  uint32 server_change_id);                     
+                  OrderDirection direction);                     
 
   // Invoked when a node is deleted.
-  OnNodeDeleted(uint32 node, uint32 server_change_id);
+  OnNodeDeleted(uint32 node);
 
   // Invoked when the view associated with a node is replaced by another view.
   // 0 is used to identify a null view.
diff --git a/mojo/services/view_manager/root_node_manager.cc b/mojo/services/view_manager/root_node_manager.cc
index 1b19bf5..fe608e8 100644
--- a/mojo/services/view_manager/root_node_manager.cc
+++ b/mojo/services/view_manager/root_node_manager.cc
@@ -20,11 +20,9 @@ namespace service {
 RootNodeManager::ScopedChange::ScopedChange(
     ViewManagerServiceImpl* connection,
     RootNodeManager* root,
-    RootNodeManager::ChangeType change_type,
     bool is_delete_node)
     : root_(root),
       connection_id_(connection->id()),
-      change_type_(change_type),
       is_delete_node_(is_delete_node) {
   root_->PrepareForChange(this);
 }
@@ -33,10 +31,6 @@ RootNodeManager::ScopedChange::~ScopedChange() {
   root_->FinishChange();
 }
 
-void RootNodeManager::ScopedChange::SendServerChangeIdAdvanced() {
-  root_->SendServerChangeIdAdvanced();
-}
-
 RootNodeManager::Context::Context() {
   // Pass in false as native viewport creates the PlatformEventSource.
   aura::Env::CreateInstance(false);
@@ -52,7 +46,6 @@ RootNodeManager::RootNodeManager(
     const Callback<void()>& native_viewport_closed_callback)
     : app_connection_(app_connection),
       next_connection_id_(1),
-      next_server_change_id_(1),
       root_view_manager_(app_connection,
                          this,
                          view_manager_delegate,
@@ -184,8 +177,7 @@ void RootNodeManager::ProcessNodeHierarchyChanged(const Node* node,
   for (ConnectionMap::iterator i = connection_map_.begin();
        i != connection_map_.end(); ++i) {
     i->second->ProcessNodeHierarchyChanged(
-        node, new_parent, old_parent, next_server_change_id_,
-        IsChangeSource(i->first));
+        node, new_parent, old_parent, IsChangeSource(i->first));
   }
 }
 
@@ -195,8 +187,7 @@ void RootNodeManager::ProcessNodeReorder(const Node* node,
   for (ConnectionMap::iterator i = connection_map_.begin();
        i != connection_map_.end(); ++i) {
     i->second->ProcessNodeReorder(
-        node, relative_node, direction, next_server_change_id_,
-        IsChangeSource(i->first));
+        node, relative_node, direction, IsChangeSource(i->first));
   }
 }
 
@@ -213,8 +204,7 @@ void RootNodeManager::ProcessNodeViewReplaced(const Node* node,
 void RootNodeManager::ProcessNodeDeleted(const NodeId& node) {
   for (ConnectionMap::iterator i = connection_map_.begin();
        i != connection_map_.end(); ++i) {
-    i->second->ProcessNodeDeleted(node, next_server_change_id_,
-                                  IsChangeSource(i->first));
+    i->second->ProcessNodeDeleted(node, IsChangeSource(i->first));
   }
 }
 
@@ -245,20 +235,9 @@ void RootNodeManager::PrepareForChange(ScopedChange* change) {
 void RootNodeManager::FinishChange() {
   // PrepareForChange/FinishChange should be balanced.
   CHECK(current_change_);
-  if (current_change_->change_type() == CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID)
-    next_server_change_id_++;
   current_change_ = NULL;
 }
 
-void RootNodeManager::SendServerChangeIdAdvanced() {
-  CHECK(current_change_);
-  for (ConnectionMap::iterator i = connection_map_.begin();
-       i != connection_map_.end(); ++i) {
-    if (!DidConnectionMessageClient(i->first))
-      i->second->client()->OnServerChangeIdAdvanced(next_server_change_id_ + 1);
-  }
-}
-
 ViewManagerServiceImpl* RootNodeManager::EmbedImpl(
     const ConnectionSpecificId creator_id,
     const String& url,
diff --git a/mojo/services/view_manager/root_node_manager.h b/mojo/services/view_manager/root_node_manager.h
index 0b20fdc..d0a4b2f 100644
--- a/mojo/services/view_manager/root_node_manager.h
+++ b/mojo/services/view_manager/root_node_manager.h
@@ -38,25 +38,16 @@ class MOJO_VIEW_MANAGER_EXPORT RootNodeManager
     : public NodeDelegate,
       public aura::client::FocusChangeObserver {
  public:
-  // Used to indicate if the server id should be incremented after notifiying
-  // clients of the change.
-  enum ChangeType {
-    CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID,
-    CHANGE_TYPE_DONT_ADVANCE_SERVER_CHANGE_ID,
-  };
-
   // Create when a ViewManagerServiceImpl is about to make a change. Ensures
   // clients are notified of the correct change id.
   class ScopedChange {
    public:
     ScopedChange(ViewManagerServiceImpl* connection,
                  RootNodeManager* root,
-                 RootNodeManager::ChangeType change_type,
                  bool is_delete_node);
     ~ScopedChange();
 
     ConnectionSpecificId connection_id() const { return connection_id_; }
-    ChangeType change_type() const { return change_type_; }
     bool is_delete_node() const { return is_delete_node_; }
 
     // Marks the connection with the specified id as having seen a message.
@@ -69,14 +60,9 @@ class MOJO_VIEW_MANAGER_EXPORT RootNodeManager
       return message_ids_.count(connection_id) > 0;
     }
 
-    // Sends OnServerChangeIdAdvanced() to all connections that have not yet
-    // been messaged.
-    void SendServerChangeIdAdvanced();
-
    private:
     RootNodeManager* root_;
     const ConnectionSpecificId connection_id_;
-    const ChangeType change_type_;
     const bool is_delete_node_;
 
     // See description of MarkConnectionAsMessaged/DidMessageConnection.
@@ -93,10 +79,6 @@ class MOJO_VIEW_MANAGER_EXPORT RootNodeManager
   // Returns the id for the next ViewManagerServiceImpl.
   ConnectionSpecificId GetAndAdvanceNextConnectionId();
 
-  Id next_server_change_id() const {
-    return next_server_change_id_;
-  }
-
   void AddConnection(ViewManagerServiceImpl* connection);
   void RemoveConnection(ViewManagerServiceImpl* connection);
 
@@ -185,9 +167,6 @@ class MOJO_VIEW_MANAGER_EXPORT RootNodeManager
   // Balances a call to PrepareForChange().
   void FinishChange();
 
-  // See description in ScopedChange.
-  void SendServerChangeIdAdvanced();
-
   // Returns true if the specified connection originated the current change.
   bool IsChangeSource(ConnectionSpecificId connection_id) const {
     return current_change_ && current_change_->connection_id() == connection_id;
@@ -219,8 +198,6 @@ class MOJO_VIEW_MANAGER_EXPORT RootNodeManager
   // ID to use for next ViewManagerServiceImpl.
   ConnectionSpecificId next_connection_id_;
 
-  Id next_server_change_id_;
-
   // Set of ViewManagerServiceImpls.
   ConnectionMap connection_map_;
 
diff --git a/mojo/services/view_manager/test_change_tracker.cc b/mojo/services/view_manager/test_change_tracker.cc
index 381e7e6..827a77d 100644
--- a/mojo/services/view_manager/test_change_tracker.cc
+++ b/mojo/services/view_manager/test_change_tracker.cc
@@ -39,11 +39,6 @@ std::string ChangeToDescription1(const Change& change) {
     case CHANGE_TYPE_ROOTS_ADDED:
       return "OnRootAdded";
 
-    case CHANGE_TYPE_SERVER_CHANGE_ID_ADVANCED:
-      return base::StringPrintf(
-          "ServerChangeIdAdvanced %d", static_cast<int>(change.change_id));
-
-
     case CHANGE_TYPE_NODE_BOUNDS_CHANGED:
       return base::StringPrintf(
           "BoundsChanged node=%s old_bounds=%s new_bounds=%s",
@@ -53,23 +48,20 @@ std::string ChangeToDescription1(const Change& change) {
 
     case CHANGE_TYPE_NODE_HIERARCHY_CHANGED:
       return base::StringPrintf(
-            "HierarchyChanged change_id=%d node=%s new_parent=%s old_parent=%s",
-            static_cast<int>(change.change_id),
+            "HierarchyChanged node=%s new_parent=%s old_parent=%s",
             NodeIdToString(change.node_id).c_str(),
             NodeIdToString(change.node_id2).c_str(),
             NodeIdToString(change.node_id3).c_str());
 
     case CHANGE_TYPE_NODE_REORDERED:
       return base::StringPrintf(
-          "Reordered change_id=%d node=%s relative=%s direction=%s",
-          static_cast<int>(change.change_id),
+          "Reordered node=%s relative=%s direction=%s",
           NodeIdToString(change.node_id).c_str(),
           NodeIdToString(change.node_id2).c_str(),
           DirectionToString(change.direction).c_str());
 
     case CHANGE_TYPE_NODE_DELETED:
-      return base::StringPrintf("NodeDeleted change_id=%d node=%s",
-                                static_cast<int>(change.change_id),
+      return base::StringPrintf("NodeDeleted node=%s",
                                 NodeIdToString(change.node_id).c_str());
 
     case CHANGE_TYPE_VIEW_DELETED:
@@ -125,7 +117,6 @@ void NodeDatasToTestNodes(const Array<NodeDataPtr>& data,
 Change::Change()
     : type(CHANGE_TYPE_CONNECTION_ESTABLISHED),
       connection_id(0),
-      change_id(0),
       node_id(0),
       node_id2(0),
       node_id3(0),
@@ -148,12 +139,10 @@ TestChangeTracker::~TestChangeTracker() {
 void TestChangeTracker::OnViewManagerConnectionEstablished(
     ConnectionSpecificId connection_id,
     const String& creator_url,
-    Id next_server_change_id,
     Array<NodeDataPtr> nodes) {
   Change change;
   change.type = CHANGE_TYPE_CONNECTION_ESTABLISHED;
   change.connection_id = connection_id;
-  change.change_id = next_server_change_id;
   change.creator_url = creator_url;
   NodeDatasToTestNodes(nodes, &change.nodes);
   AddChange(change);
@@ -166,13 +155,6 @@ void TestChangeTracker::OnRootAdded(Array<NodeDataPtr> nodes) {
   AddChange(change);
 }
 
-void TestChangeTracker::OnServerChangeIdAdvanced(Id change_id) {
-  Change change;
-  change.type = CHANGE_TYPE_SERVER_CHANGE_ID_ADVANCED;
-  change.change_id = change_id;
-  AddChange(change);
-}
-
 void TestChangeTracker::OnNodeBoundsChanged(Id node_id,
                                             RectPtr old_bounds,
                                             RectPtr new_bounds) {
@@ -187,36 +169,31 @@ void TestChangeTracker::OnNodeBoundsChanged(Id node_id,
 void TestChangeTracker::OnNodeHierarchyChanged(Id node_id,
                                                Id new_parent_id,
                                                Id old_parent_id,
-                                               Id server_change_id,
                                                Array<NodeDataPtr> nodes) {
   Change change;
   change.type = CHANGE_TYPE_NODE_HIERARCHY_CHANGED;
   change.node_id = node_id;
   change.node_id2 = new_parent_id;
   change.node_id3 = old_parent_id;
-  change.change_id = server_change_id;
   NodeDatasToTestNodes(nodes, &change.nodes);
   AddChange(change);
 }
 
 void TestChangeTracker::OnNodeReordered(Id node_id,
                                         Id relative_node_id,
-                                        OrderDirection direction,
-                                        Id server_change_id) {
+                                        OrderDirection direction) {
   Change change;
   change.type = CHANGE_TYPE_NODE_REORDERED;
   change.node_id = node_id;
   change.node_id2 = relative_node_id;
   change.direction = direction;
-  change.change_id = server_change_id;
   AddChange(change);
 }
 
-void TestChangeTracker::OnNodeDeleted(Id node_id, Id server_change_id) {
+void TestChangeTracker::OnNodeDeleted(Id node_id) {
   Change change;
   change.type = CHANGE_TYPE_NODE_DELETED;
   change.node_id = node_id;
-  change.change_id = server_change_id;
   AddChange(change);
 }
 
diff --git a/mojo/services/view_manager/test_change_tracker.h b/mojo/services/view_manager/test_change_tracker.h
index 6021611..d597c6f 100644
--- a/mojo/services/view_manager/test_change_tracker.h
+++ b/mojo/services/view_manager/test_change_tracker.h
@@ -20,7 +20,6 @@ namespace service {
 enum ChangeType {
   CHANGE_TYPE_CONNECTION_ESTABLISHED,
   CHANGE_TYPE_ROOTS_ADDED,
-  CHANGE_TYPE_SERVER_CHANGE_ID_ADVANCED,
   CHANGE_TYPE_NODE_BOUNDS_CHANGED,
   CHANGE_TYPE_NODE_HIERARCHY_CHANGED,
   CHANGE_TYPE_NODE_REORDERED,
@@ -48,7 +47,6 @@ struct Change {
 
   ChangeType type;
   ConnectionSpecificId connection_id;
-  Id change_id;
   std::vector<TestNode> nodes;
   Id node_id;
   Id node_id2;
@@ -99,21 +97,17 @@ class TestChangeTracker {
   // ViewManagerClient function.
   void OnViewManagerConnectionEstablished(ConnectionSpecificId connection_id,
                                           const String& creator_url,
-                                          Id next_server_change_id,
                                           Array<NodeDataPtr> nodes);
   void OnRootAdded(Array<NodeDataPtr> nodes);
-  void OnServerChangeIdAdvanced(Id change_id);
   void OnNodeBoundsChanged(Id node_id, RectPtr old_bounds, RectPtr new_bounds);
   void OnNodeHierarchyChanged(Id node_id,
                               Id new_parent_id,
                               Id old_parent_id,
-                              Id server_change_id,
                               Array<NodeDataPtr> nodes);
   void OnNodeReordered(Id node_id,
                        Id relative_node_id,
-                       OrderDirection direction,
-                       Id server_change_id);
-  void OnNodeDeleted(Id node_id, Id server_change_id);
+                       OrderDirection direction);
+  void OnNodeDeleted(Id node_id);
   void OnViewDeleted(Id view_id);
   void OnNodeViewReplaced(Id node_id, Id new_view_id, Id old_view_id);
   void OnViewInputEvent(Id view_id, EventPtr event);
diff --git a/mojo/services/view_manager/view_manager_service_impl.cc b/mojo/services/view_manager/view_manager_service_impl.cc
index 793a4543..ee2c795 100644
--- a/mojo/services/view_manager/view_manager_service_impl.cc
+++ b/mojo/services/view_manager/view_manager_service_impl.cc
@@ -60,9 +60,7 @@ ViewManagerServiceImpl::~ViewManagerServiceImpl() {
 
   // Ditto the nodes.
   if (!node_map_.empty()) {
-    RootNodeManager::ScopedChange change(
-        this, root_node_manager_,
-        RootNodeManager::CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID, true);
+    RootNodeManager::ScopedChange change(this, root_node_manager_, true);
     while (!node_map_.empty())
       delete node_map_.begin()->second;
   }
@@ -115,7 +113,6 @@ void ViewManagerServiceImpl::ProcessNodeHierarchyChanged(
     const Node* node,
     const Node* new_parent,
     const Node* old_parent,
-    Id server_change_id,
     bool originated_change) {
   if (known_nodes_.count(NodeIdToTransportId(node->id())) > 0) {
     if (originated_change)
@@ -124,8 +121,7 @@ void ViewManagerServiceImpl::ProcessNodeHierarchyChanged(
       // Node was a descendant of roots and is no longer, treat it as though the
       // node was deleted.
       RemoveFromKnown(node, NULL);
-      client()->OnNodeDeleted(NodeIdToTransportId(node->id()),
-                              server_change_id);
+      client()->OnNodeDeleted(NodeIdToTransportId(node->id()));
       root_node_manager_->OnConnectionMessagedClient(id_);
       return;
     }
@@ -136,10 +132,6 @@ void ViewManagerServiceImpl::ProcessNodeHierarchyChanged(
   std::vector<const Node*> to_send;
   if (!ShouldNotifyOnHierarchyChange(node, &new_parent, &old_parent,
                                      &to_send)) {
-    if (root_node_manager_->IsProcessingChange()) {
-      client()->OnServerChangeIdAdvanced(
-          root_node_manager_->next_server_change_id() + 1);
-    }
     return;
   }
   const NodeId new_parent_id(new_parent ? new_parent->id() : NodeId());
@@ -151,14 +143,12 @@ void ViewManagerServiceImpl::ProcessNodeHierarchyChanged(
   client()->OnNodeHierarchyChanged(NodeIdToTransportId(node->id()),
                                    NodeIdToTransportId(new_parent_id),
                                    NodeIdToTransportId(old_parent_id),
-                                   server_change_id,
                                    NodesToNodeDatas(to_send));
 }
 
 void ViewManagerServiceImpl::ProcessNodeReorder(const Node* node,
                                                 const Node* relative_node,
                                                 OrderDirection direction,
-                                                Id server_change_id,
                                                 bool originated_change) {
   if (originated_change ||
       !known_nodes_.count(NodeIdToTransportId(node->id())) ||
@@ -168,8 +158,7 @@ void ViewManagerServiceImpl::ProcessNodeReorder(const Node* node,
 
   client()->OnNodeReordered(NodeIdToTransportId(node->id()),
                             NodeIdToTransportId(relative_node->id()),
-                            direction,
-                            server_change_id);
+                            direction);
 }
 
 void ViewManagerServiceImpl::ProcessNodeViewReplaced(
@@ -188,7 +177,6 @@ void ViewManagerServiceImpl::ProcessNodeViewReplaced(
 }
 
 void ViewManagerServiceImpl::ProcessNodeDeleted(const NodeId& node,
-                                                Id server_change_id,
                                                 bool originated_change) {
   node_map_.erase(node.node_id);
 
@@ -202,12 +190,10 @@ void ViewManagerServiceImpl::ProcessNodeDeleted(const NodeId& node,
     return;
 
   if (in_known) {
-    client()->OnNodeDeleted(NodeIdToTransportId(node), server_change_id);
+    client()->OnNodeDeleted(NodeIdToTransportId(node));
     root_node_manager_->OnConnectionMessagedClient(id_);
   } else if (root_node_manager_->IsProcessingChange() &&
              !root_node_manager_->DidConnectionMessageClient(id_)) {
-    client()->OnServerChangeIdAdvanced(
-        root_node_manager_->next_server_change_id() + 1);
     root_node_manager_->OnConnectionMessagedClient(id_);
   }
 }
@@ -361,9 +347,7 @@ bool ViewManagerServiceImpl::DeleteNodeImpl(ViewManagerServiceImpl* source,
   Node* node = GetNode(node_id);
   if (!node)
     return false;
-  RootNodeManager::ScopedChange change(
-      source, root_node_manager_,
-      RootNodeManager::CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID, true);
+  RootNodeManager::ScopedChange change(source, root_node_manager_, true);
   delete node;
   return true;
 }
@@ -374,9 +358,7 @@ bool ViewManagerServiceImpl::DeleteViewImpl(ViewManagerServiceImpl* source,
   View* view = GetView(view_id);
   if (!view)
     return false;
-  RootNodeManager::ScopedChange change(
-      source, root_node_manager_,
-      RootNodeManager::CHANGE_TYPE_DONT_ADVANCE_SERVER_CHANGE_ID, false);
+  RootNodeManager::ScopedChange change(source, root_node_manager_, false);
   if (view->node())
     view->node()->SetView(NULL);
   view_map_.erase(view_id.view_id);
@@ -391,9 +373,7 @@ bool ViewManagerServiceImpl::DeleteViewImpl(ViewManagerServiceImpl* source,
 bool ViewManagerServiceImpl::SetViewImpl(Node* node, const ViewId& view_id) {
   DCHECK(node);  // CanSetView() should have verified node exists.
   View* view = GetView(view_id);
-  RootNodeManager::ScopedChange change(
-      this, root_node_manager_,
-      RootNodeManager::CHANGE_TYPE_DONT_ADVANCE_SERVER_CHANGE_ID, false);
+  RootNodeManager::ScopedChange change(this, root_node_manager_, false);
   node->SetView(view);
   return true;
 }
@@ -457,8 +437,7 @@ void ViewManagerServiceImpl::RemoveRoot(const NodeId& node_id) {
   if (node_id.connection_id == id_)
     return;
 
-  client()->OnNodeDeleted(transport_node_id,
-                          root_node_manager_->next_server_change_id());
+  client()->OnNodeDeleted(transport_node_id);
   root_node_manager_->OnConnectionMessagedClient(id_);
 
   // This connection no longer knows about the node. Unparent any nodes that
@@ -572,12 +551,10 @@ void ViewManagerServiceImpl::CreateNode(
 
 void ViewManagerServiceImpl::DeleteNode(
     Id transport_node_id,
-    Id server_change_id,
     const Callback<void(bool)>& callback) {
   const NodeId node_id(NodeIdFromTransportId(transport_node_id));
   bool success = false;
-  if (server_change_id == root_node_manager_->next_server_change_id() &&
-      CanDeleteNode(node_id)) {
+  if (CanDeleteNode(node_id)) {
     ViewManagerServiceImpl* connection = root_node_manager_->GetConnection(
         node_id.connection_id);
     success = connection && connection->DeleteNodeImpl(this, node_id);
@@ -588,37 +565,27 @@ void ViewManagerServiceImpl::DeleteNode(
 void ViewManagerServiceImpl::AddNode(
     Id parent_id,
     Id child_id,
-    Id server_change_id,
     const Callback<void(bool)>& callback) {
   bool success = false;
-  if (server_change_id == root_node_manager_->next_server_change_id()) {
-    Node* parent = GetNode(NodeIdFromTransportId(parent_id));
-    Node* child = GetNode(NodeIdFromTransportId(child_id));
-    if (CanAddNode(parent, child)) {
-      success = true;
-      RootNodeManager::ScopedChange change(
-          this, root_node_manager_,
-          RootNodeManager::CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID, false);
-      parent->Add(child);
-    }
+  Node* parent = GetNode(NodeIdFromTransportId(parent_id));
+  Node* child = GetNode(NodeIdFromTransportId(child_id));
+  if (CanAddNode(parent, child)) {
+    success = true;
+    RootNodeManager::ScopedChange change(this, root_node_manager_, false);
+    parent->Add(child);
   }
   callback.Run(success);
 }
 
 void ViewManagerServiceImpl::RemoveNodeFromParent(
     Id node_id,
-    Id server_change_id,
     const Callback<void(bool)>& callback) {
   bool success = false;
-  if (server_change_id == root_node_manager_->next_server_change_id()) {
-    Node* node = GetNode(NodeIdFromTransportId(node_id));
-    if (CanRemoveNodeFromParent(node)) {
-      success = true;
-      RootNodeManager::ScopedChange change(
-          this, root_node_manager_,
-          RootNodeManager::CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID, false);
-      node->GetParent()->Remove(node);
-    }
+  Node* node = GetNode(NodeIdFromTransportId(node_id));
+  if (CanRemoveNodeFromParent(node)) {
+    success = true;
+    RootNodeManager::ScopedChange change(this, root_node_manager_, false);
+    node->GetParent()->Remove(node);
   }
   callback.Run(success);
 }
@@ -626,20 +593,15 @@ void ViewManagerServiceImpl::RemoveNodeFromParent(
 void ViewManagerServiceImpl::ReorderNode(Id node_id,
                                          Id relative_node_id,
                                          OrderDirection direction,
-                                         Id server_change_id,
                                          const Callback<void(bool)>& callback) {
   bool success = false;
-  if (server_change_id == root_node_manager_->next_server_change_id()) {
-    Node* node = GetNode(NodeIdFromTransportId(node_id));
-    Node* relative_node = GetNode(NodeIdFromTransportId(relative_node_id));
-    if (CanReorderNode(node, relative_node, direction)) {
-      success = true;
-      RootNodeManager::ScopedChange change(
-          this, root_node_manager_,
-          RootNodeManager::CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID, false);
-      node->GetParent()->Reorder(node, relative_node, direction);
-      root_node_manager_->ProcessNodeReorder(node, relative_node, direction);
-    }
+  Node* node = GetNode(NodeIdFromTransportId(node_id));
+  Node* relative_node = GetNode(NodeIdFromTransportId(relative_node_id));
+  if (CanReorderNode(node, relative_node, direction)) {
+    success = true;
+    RootNodeManager::ScopedChange change(this, root_node_manager_, false);
+    node->GetParent()->Reorder(node, relative_node, direction);
+    root_node_manager_->ProcessNodeReorder(node, relative_node, direction);
   }
   callback.Run(success);
 }
@@ -740,9 +702,7 @@ void ViewManagerServiceImpl::SetNodeBounds(
     return;
   }
 
-  RootNodeManager::ScopedChange change(
-      this, root_node_manager_,
-      RootNodeManager::CHANGE_TYPE_DONT_ADVANCE_SERVER_CHANGE_ID, false);
+  RootNodeManager::ScopedChange change(this, root_node_manager_, false);
   gfx::Rect old_bounds = node->window()->bounds();
   node->window()->SetBounds(bounds.To<gfx::Rect>());
   callback.Run(true);
@@ -777,9 +737,7 @@ void ViewManagerServiceImpl::Embed(const String& url,
     if ((connection_by_url != connection_with_node_as_root ||
          (!connection_by_url && !connection_with_node_as_root)) &&
         (!connection_by_url || !connection_by_url->HasRoot(node_id))) {
-      RootNodeManager::ScopedChange change(
-          this, root_node_manager_,
-          RootNodeManager::CHANGE_TYPE_ADVANCE_SERVER_CHANGE_ID, true);
+      RootNodeManager::ScopedChange change(this, root_node_manager_, true);
       // Never message the originating connection.
       root_node_manager_->OnConnectionMessagedClient(id_);
       if (connection_with_node_as_root)
@@ -788,7 +746,6 @@ void ViewManagerServiceImpl::Embed(const String& url,
         connection_by_url->AddRoot(node_id);
       else
         root_node_manager_->Embed(id_, url, transport_node_id);
-      change.SendServerChangeIdAdvanced();
     } else {
       success = false;
     }
@@ -828,7 +785,6 @@ void ViewManagerServiceImpl::OnConnectionEstablished() {
   client()->OnViewManagerConnectionEstablished(
       id_,
       creator_url_,
-      root_node_manager_->next_server_change_id(),
       NodesToNodeDatas(to_send));
 }
 
diff --git a/mojo/services/view_manager/view_manager_service_impl.h b/mojo/services/view_manager/view_manager_service_impl.h
index b9b6de27..00b61cb 100644
--- a/mojo/services/view_manager/view_manager_service_impl.h
+++ b/mojo/services/view_manager/view_manager_service_impl.h
@@ -84,20 +84,16 @@ class MOJO_VIEW_MANAGER_EXPORT ViewManagerServiceImpl
   void ProcessNodeHierarchyChanged(const Node* node,
                                    const Node* new_parent,
                                    const Node* old_parent,
-                                   Id server_change_id,
                                    bool originated_change);
   void ProcessNodeReorder(const Node* node,
                           const Node* relative_node,
                           OrderDirection direction,
-                          Id server_change_id,
                           bool originated_change);
   void ProcessNodeViewReplaced(const Node* node,
                                const View* new_view,
                                const View* old_view,
                                bool originated_change);
-  void ProcessNodeDeleted(const NodeId& node,
-                          Id server_change_id,
-                          bool originated_change);
+  void ProcessNodeDeleted(const NodeId& node, bool originated_change);
   void ProcessViewDeleted(const ViewId& view, bool originated_change);
   void ProcessFocusChanged(const Node* focused_node,
                            const Node* blurred_node,
@@ -176,20 +172,16 @@ class MOJO_VIEW_MANAGER_EXPORT ViewManagerServiceImpl
   virtual void CreateNode(Id transport_node_id,
                           const Callback<void(ErrorCode)>& callback) OVERRIDE;
   virtual void DeleteNode(Id transport_node_id,
-                          Id server_change_id,
                           const Callback<void(bool)>& callback) OVERRIDE;
   virtual void AddNode(Id parent_id,
                        Id child_id,
-                       Id server_change_id,
                        const Callback<void(bool)>& callback) OVERRIDE;
   virtual void RemoveNodeFromParent(
       Id node_id,
-      Id server_change_id,
       const Callback<void(bool)>& callback) OVERRIDE;
   virtual void ReorderNode(Id node_id,
                            Id relative_node_id,
                            OrderDirection direction,
-                           Id server_change_id,
                            const Callback<void(bool)>& callback) OVERRIDE;
   virtual void GetNodeTree(
       Id node_id,
diff --git a/mojo/services/view_manager/view_manager_unittest.cc b/mojo/services/view_manager/view_manager_unittest.cc
index e630147..73153737 100644
--- a/mojo/services/view_manager/view_manager_unittest.cc
+++ b/mojo/services/view_manager/view_manager_unittest.cc
@@ -117,19 +117,19 @@ class ViewManagerProxy : public TestChangeTracker::Delegate {
     RunMainLoop();
     return result;
   }
-  bool AddNode(Id parent, Id child, Id server_change_id) {
+  bool AddNode(Id parent, Id child) {
     changes_.clear();
     bool result = false;
-    view_manager_->AddNode(parent, child, server_change_id,
+    view_manager_->AddNode(parent, child,
                            base::Bind(&ViewManagerProxy::GotResult,
                                       base::Unretained(this), &result));
     RunMainLoop();
     return result;
   }
-  bool RemoveNodeFromParent(Id node_id, Id server_change_id) {
+  bool RemoveNodeFromParent(Id node_id) {
     changes_.clear();
     bool result = false;
-    view_manager_->RemoveNodeFromParent(node_id, server_change_id,
+    view_manager_->RemoveNodeFromParent(node_id,
         base::Bind(&ViewManagerProxy::GotResult,
                    base::Unretained(this), &result));
     RunMainLoop();
@@ -137,12 +137,10 @@ class ViewManagerProxy : public TestChangeTracker::Delegate {
   }
   bool ReorderNode(Id node_id,
                    Id relative_node_id,
-                   OrderDirection direction,
-                   Id server_change_id) {
+                   OrderDirection direction) {
     changes_.clear();
     bool result = false;
     view_manager_->ReorderNode(node_id, relative_node_id, direction,
-                               server_change_id,
                                base::Bind(&ViewManagerProxy::GotResult,
                                           base::Unretained(this), &result));
     RunMainLoop();
@@ -183,11 +181,10 @@ class ViewManagerProxy : public TestChangeTracker::Delegate {
     RunMainLoop();
     return result;
   }
-  bool DeleteNode(Id node_id, Id server_change_id) {
+  bool DeleteNode(Id node_id) {
     changes_.clear();
     bool result = false;
     view_manager_->DeleteNode(node_id,
-                              server_change_id,
                               base::Bind(&ViewManagerProxy::GotResult,
                                          base::Unretained(this), &result));
     RunMainLoop();
@@ -325,18 +322,13 @@ class TestViewManagerClientConnection
   virtual void OnViewManagerConnectionEstablished(
       ConnectionSpecificId connection_id,
       const String& creator_url,
-      Id next_server_change_id,
       Array<NodeDataPtr> nodes) OVERRIDE {
     tracker_.OnViewManagerConnectionEstablished(
-        connection_id, creator_url, next_server_change_id, nodes.Pass());
+        connection_id, creator_url, nodes.Pass());
   }
   virtual void OnRootAdded(Array<NodeDataPtr> nodes) OVERRIDE {
     tracker_.OnRootAdded(nodes.Pass());
   }
-  virtual void OnServerChangeIdAdvanced(
-      Id next_server_change_id) OVERRIDE {
-    tracker_.OnServerChangeIdAdvanced(next_server_change_id);
-  }
   virtual void OnNodeBoundsChanged(Id node_id,
                                    RectPtr old_bounds,
                                    RectPtr new_bounds) OVERRIDE {
@@ -345,20 +337,16 @@ class TestViewManagerClientConnection
   virtual void OnNodeHierarchyChanged(Id node,
                                       Id new_parent,
                                       Id old_parent,
-                                      Id server_change_id,
                                       Array<NodeDataPtr> nodes) OVERRIDE {
-    tracker_.OnNodeHierarchyChanged(node, new_parent, old_parent,
-                                    server_change_id, nodes.Pass());
+    tracker_.OnNodeHierarchyChanged(node, new_parent, old_parent, nodes.Pass());
   }
   virtual void OnNodeReordered(Id node_id,
                                Id relative_node_id,
-                               OrderDirection direction,
-                               Id server_change_id) OVERRIDE {
-    tracker_.OnNodeReordered(node_id, relative_node_id, direction,
-                             server_change_id);
+                               OrderDirection direction) OVERRIDE {
+    tracker_.OnNodeReordered(node_id, relative_node_id, direction);
   }
-  virtual void OnNodeDeleted(Id node, Id server_change_id) OVERRIDE {
-    tracker_.OnNodeDeleted(node, server_change_id);
+  virtual void OnNodeDeleted(Id node) OVERRIDE {
+    tracker_.OnNodeDeleted(node);
   }
   virtual void OnViewDeleted(Id view) OVERRIDE {
     tracker_.OnViewDeleted(view);
@@ -539,9 +527,6 @@ TEST_F(ViewManagerTest, ValidId) {
   // All these tests assume 1 for the client id. The only real assertion here is
   // the client id is not zero, but adding this as rest of code here assumes 1.
   EXPECT_EQ(1, connection_->changes()[0].connection_id);
-
-  // Change ids start at 1 as well.
-  EXPECT_EQ(static_cast<Id>(1), connection_->changes()[0].change_id);
 }
 
 // Verifies two clients/connections get different ids.
@@ -554,9 +539,6 @@ TEST_F(ViewManagerTest, TwoClientsGetDifferentConnectionIds) {
   // tests are written assuming that is the case. The key thing is the
   // connection ids of |connection_| and |connection2_| differ.
   EXPECT_EQ(2, connection2_->changes()[0].connection_id);
-
-  // Change ids start at 1 as well.
-  EXPECT_EQ(static_cast<Id>(1), connection2_->changes()[0].change_id);
 }
 
 // Verifies client gets a valid id.
@@ -570,9 +552,8 @@ TEST_F(ViewManagerTest, CreateNode) {
   EXPECT_TRUE(connection_->changes().empty());
 
   // Can't create a node with a bogus connection id.
-  EXPECT_EQ(
-      ERROR_CODE_ILLEGAL_ARGUMENT,
-      connection_->CreateNodeWithErrorCode(BuildNodeId(2, 1)));
+  EXPECT_EQ(ERROR_CODE_ILLEGAL_ARGUMENT,
+            connection_->CreateNodeWithErrorCode(BuildNodeId(2, 1)));
   EXPECT_TRUE(connection_->changes().empty());
 }
 
@@ -581,36 +562,6 @@ TEST_F(ViewManagerTest, CreateViewFailsWithBogusConnectionId) {
   EXPECT_TRUE(connection_->changes().empty());
 }
 
-// Verifies hierarchy changes.
-TEST_F(ViewManagerTest, AddRemoveNotify) {
-  ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
-  ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 3)));
-
-  ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
-
-  // Make 3 a child of 2.
-  {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3), 2));
-    EXPECT_TRUE(connection_->changes().empty());
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 3", changes[0]);
-  }
-
-  // Remove 3 from its parent.
-  {
-    ASSERT_TRUE(connection_->RemoveNodeFromParent(BuildNodeId(1, 3), 3));
-    EXPECT_TRUE(connection_->changes().empty());
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 4", changes[0]);
-  }
-}
-
 // Verifies AddNode fails when node is already in position.
 TEST_F(ViewManagerTest, AddNodeWithNoChange) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
@@ -619,19 +570,10 @@ TEST_F(ViewManagerTest, AddNodeWithNoChange) {
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
 
   // Make 3 a child of 2.
-  {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3), 2));
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 3", changes[0]);
-  }
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3)));
 
   // Try again, this should fail.
-  {
-    EXPECT_FALSE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3), 3));
-  }
+  EXPECT_FALSE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3)));
 }
 
 // Verifies AddNode fails when node is already in position.
@@ -642,28 +584,10 @@ TEST_F(ViewManagerTest, AddAncestorFails) {
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
 
   // Make 3 a child of 2.
-  {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3), 2));
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 3", changes[0]);
-  }
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 3)));
 
   // Try to make 2 a child of 3, this should fail since 2 is an ancestor of 3.
-  {
-    EXPECT_FALSE(connection_->AddNode(BuildNodeId(1, 3), BuildNodeId(1, 2), 3));
-  }
-}
-
-// Verifies adding with an invalid id fails.
-TEST_F(ViewManagerTest, AddWithInvalidServerId) {
-  // Create two nodes.
-  ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 1)));
-  ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
-
-  // Make 2 a child of 1. Supply an invalid change id, which should fail.
-  ASSERT_FALSE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 0));
+  EXPECT_FALSE(connection_->AddNode(BuildNodeId(1, 3), BuildNodeId(1, 2)));
 }
 
 // Verifies adding to root sends right notifications.
@@ -674,25 +598,17 @@ TEST_F(ViewManagerTest, AddToRoot) {
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
 
   // Make 3 a child of 21.
-  {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 21), BuildNodeId(1, 3), 2));
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 3", changes[0]);
-  }
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 21), BuildNodeId(1, 3)));
 
   // Make 21 a child of 1.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 21), 3));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 21)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=3 node=1,21 new_parent=1,1 old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,21 new_parent=1,1 old_parent=null",
+              changes[0]);
   }
 }
 
@@ -701,13 +617,13 @@ TEST_F(ViewManagerTest, NodeHierarchyChangedNodes) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 11)));
   // Make 11 a child of 2.
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 11), 1));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 11)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
 
   // Make 2 a child of 1.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 3));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
 
     // Client 2 should get a hierarchy change that includes the new nodes as it
     // has not yet seen them.
@@ -715,8 +631,7 @@ TEST_F(ViewManagerTest, NodeHierarchyChangedNodes) {
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
     EXPECT_EQ(
-        "HierarchyChanged change_id=3 node=1,2 new_parent=1,1 old_parent=null",
-        changes[0]);
+        "HierarchyChanged node=1,2 new_parent=1,1 old_parent=null", changes[0]);
     EXPECT_EQ("[node=1,2 parent=1,1 view=null],"
               "[node=1,11 parent=1,2 view=null]",
               ChangeNodeDescription(connection2_->changes()));
@@ -724,58 +639,53 @@ TEST_F(ViewManagerTest, NodeHierarchyChangedNodes) {
 
   // Add 1 to the root.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 4));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
 
     // Client 2 should get a hierarchy change that includes the new nodes as it
     // has not yet seen them.
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=4 node=1,1 new_parent=null old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,1 new_parent=null old_parent=null",
+              changes[0]);
     EXPECT_EQ(std::string(), ChangeNodeDescription(connection2_->changes()));
   }
 
   // Remove 1 from its parent.
   {
-    ASSERT_TRUE(connection_->RemoveNodeFromParent(BuildNodeId(1, 1), 5));
+    ASSERT_TRUE(connection_->RemoveNodeFromParent(BuildNodeId(1, 1)));
     EXPECT_TRUE(connection_->changes().empty());
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=5 node=1,1 new_parent=null old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,1 new_parent=null old_parent=null",
+              changes[0]);
   }
 
   // Create another node, 111, parent it to 11.
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 111)));
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 11), BuildNodeId(1, 111),
-                                     6));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 11), BuildNodeId(1, 111)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=6 node=1,111 new_parent=1,11 "
-        "old_parent=null", changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,111 new_parent=1,11 old_parent=null",
+              changes[0]);
     EXPECT_EQ("[node=1,111 parent=1,11 view=null]",
               ChangeNodeDescription(connection2_->changes()));
   }
 
   // Reattach 1 to the root.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 7));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=7 node=1,1 new_parent=null old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,1 new_parent=null old_parent=null",
+              changes[0]);
     EXPECT_EQ(std::string(), ChangeNodeDescription(connection2_->changes()));
   }
 }
@@ -789,38 +699,35 @@ TEST_F(ViewManagerTest, NodeHierarchyChangedAddingKnownToUnknown) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 21)));
 
   // Set up the hierarchy.
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 11), 2));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 21), 3));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 11)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 21)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
-  {
-    EXPECT_EQ("[node=1,1 parent=null view=null],"
-              "[node=1,11 parent=1,1 view=null]",
-              ChangeNodeDescription(connection2_->changes()));
-  }
+  EXPECT_EQ("[node=1,1 parent=null view=null],"
+            "[node=1,11 parent=1,1 view=null]",
+            ChangeNodeDescription(connection2_->changes()));
 
   // Remove 11, should result in a delete (since 11 is no longer in connection
   // 2's root).
   {
-    ASSERT_TRUE(connection_->RemoveNodeFromParent(BuildNodeId(1, 11), 5));
+    ASSERT_TRUE(connection_->RemoveNodeFromParent(BuildNodeId(1, 11)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("NodeDeleted change_id=5 node=1,11", changes[0]);
+    EXPECT_EQ("NodeDeleted node=1,11", changes[0]);
   }
 
   // Add 2 to 1.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 6));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=6 node=1,2 new_parent=1,1 old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,2 new_parent=1,1 old_parent=null",
+              changes[0]);
     EXPECT_EQ("[node=1,2 parent=1,1 view=null],"
               "[node=1,21 parent=1,2 view=null]",
               ChangeNodeDescription(connection2_->changes()));
@@ -844,67 +751,55 @@ TEST_F(ViewManagerTest, ReorderNode) {
   ASSERT_TRUE(connection_->CreateNode(node6_id));
   ASSERT_TRUE(connection_->CreateNode(node7_id));
   ASSERT_TRUE(connection_->CreateNode(node8_id));
-  ASSERT_TRUE(connection_->AddNode(node1_id, node2_id, 1));
-  ASSERT_TRUE(connection_->AddNode(node2_id, node6_id, 2));
-  ASSERT_TRUE(connection_->AddNode(node1_id, node3_id, 3));
+  ASSERT_TRUE(connection_->AddNode(node1_id, node2_id));
+  ASSERT_TRUE(connection_->AddNode(node2_id, node6_id));
+  ASSERT_TRUE(connection_->AddNode(node1_id, node3_id));
   ASSERT_TRUE(connection_->AddNode(
-      NodeIdToTransportId(RootNodeId()), node4_id, 4));
+      NodeIdToTransportId(RootNodeId()), node4_id));
   ASSERT_TRUE(connection_->AddNode(
-      NodeIdToTransportId(RootNodeId()), node5_id, 5));
+      NodeIdToTransportId(RootNodeId()), node5_id));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
   {
-    connection_->ReorderNode(node2_id, node3_id, ORDER_DIRECTION_ABOVE, 7);
+    connection_->ReorderNode(node2_id, node3_id, ORDER_DIRECTION_ABOVE);
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "Reordered change_id=7 node=1,2 relative=1,3 direction=above",
-        changes[0]);
+    EXPECT_EQ("Reordered node=1,2 relative=1,3 direction=above",
+              changes[0]);
   }
 
   {
-    connection_->ReorderNode(node2_id, node3_id, ORDER_DIRECTION_BELOW, 8);
+    connection_->ReorderNode(node2_id, node3_id, ORDER_DIRECTION_BELOW);
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "Reordered change_id=8 node=1,2 relative=1,3 direction=below",
-        changes[0]);
+    EXPECT_EQ("Reordered node=1,2 relative=1,3 direction=below",
+              changes[0]);
   }
 
-  {
-    // node2 is already below node3.
-    EXPECT_FALSE(
-        connection_->ReorderNode(node2_id, node3_id, ORDER_DIRECTION_BELOW, 9));
-  }
+  // node2 is already below node3.
+  EXPECT_FALSE(
+      connection_->ReorderNode(node2_id, node3_id, ORDER_DIRECTION_BELOW));
 
-  {
-    // node4 & 5 are unknown to connection2_.
-    EXPECT_FALSE(connection2_->ReorderNode(
-        node4_id, node5_id, ORDER_DIRECTION_ABOVE, 9));
-  }
+  // node4 & 5 are unknown to connection2_.
+  EXPECT_FALSE(connection2_->ReorderNode(
+                   node4_id, node5_id, ORDER_DIRECTION_ABOVE));
 
-  {
-    // node6 & node3 have different parents.
-    EXPECT_FALSE(
-        connection_->ReorderNode(node3_id, node6_id, ORDER_DIRECTION_ABOVE, 9));
-  }
+  // node6 & node3 have different parents.
+  EXPECT_FALSE(
+      connection_->ReorderNode(node3_id, node6_id, ORDER_DIRECTION_ABOVE));
 
-  {
-    // Non-existent node-ids
-    EXPECT_FALSE(connection_->ReorderNode(
-        BuildNodeId(1, 27), BuildNodeId(1, 28), ORDER_DIRECTION_ABOVE, 9));
-  }
+  // Non-existent node-ids
+  EXPECT_FALSE(connection_->ReorderNode(
+      BuildNodeId(1, 27), BuildNodeId(1, 28), ORDER_DIRECTION_ABOVE));
 
-  {
-    // node7 & node8 are un-parented.
-    EXPECT_FALSE(
-        connection_->ReorderNode(node7_id, node8_id, ORDER_DIRECTION_ABOVE, 9));
-  }
+  // node7 & node8 are un-parented.
+  EXPECT_FALSE(
+      connection_->ReorderNode(node7_id, node8_id, ORDER_DIRECTION_ABOVE));
 }
 
 // Verifies DeleteNode works.
@@ -915,30 +810,30 @@ TEST_F(ViewManagerTest, DeleteNode) {
 
   // Make 2 a child of 1.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 2));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("HierarchyChanged change_id=2 node=1,2 new_parent=1,1 "
-              "old_parent=null", changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,2 new_parent=1,1 old_parent=null",
+              changes[0]);
   }
 
   // Delete 2.
   {
-    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 2), 3));
+    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 2)));
     EXPECT_TRUE(connection_->changes().empty());
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("NodeDeleted change_id=3 node=1,2", changes[0]);
+    EXPECT_EQ("NodeDeleted node=1,2", changes[0]);
   }
 }
 
 // Verifies DeleteNode isn't allowed from a separate connection.
 TEST_F(ViewManagerTest, DeleteNodeFromAnotherConnectionDisallowed) {
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(true));
-  EXPECT_FALSE(connection2_->DeleteNode(BuildNodeId(1, 1), 1));
+  EXPECT_FALSE(connection2_->DeleteNode(BuildNodeId(1, 1)));
 }
 
 // Verifies DeleteView isn't allowed from a separate connection.
@@ -956,37 +851,35 @@ TEST_F(ViewManagerTest, ReuseDeletedNodeId) {
 
   // Add 2 to 1.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 2));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
-    EXPECT_EQ(
-        "HierarchyChanged change_id=2 node=1,2 new_parent=1,1 old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,2 new_parent=1,1 old_parent=null",
+              changes[0]);
     EXPECT_EQ("[node=1,2 parent=1,1 view=null]",
               ChangeNodeDescription(connection2_->changes()));
   }
 
   // Delete 2.
   {
-    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 2), 3));
+    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 2)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("NodeDeleted change_id=3 node=1,2", changes[0]);
+    EXPECT_EQ("NodeDeleted node=1,2", changes[0]);
   }
 
   // Create 2 again, and add it back to 1. Should get the same notification.
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 4));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
-    EXPECT_EQ(
-        "HierarchyChanged change_id=4 node=1,2 new_parent=1,1 old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=1,2 new_parent=1,1 old_parent=null",
+              changes[0]);
     EXPECT_EQ("[node=1,2 parent=1,1 view=null]",
               ChangeNodeDescription(connection2_->changes()));
   }
@@ -999,8 +892,8 @@ TEST_F(ViewManagerTest, SetView) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 3)));
   ASSERT_TRUE(connection_->CreateView(BuildViewId(1, 11)));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 1));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 3), 2));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 3)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
@@ -1044,17 +937,10 @@ TEST_F(ViewManagerTest, DeleteNodeWithView) {
 
   // Delete node 2. The second connection should not see this because the node
   // was not known to it.
-  {
-    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 2), 2));
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 3", changes[0]);
-  }
+  ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 2)));
 
   // Parent 3 to 1.
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 3), 3));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 3)));
   connection2_->DoRunLoopUntilChangesCount(1);
 
   // Set view 11 on node 3.
@@ -1069,12 +955,12 @@ TEST_F(ViewManagerTest, DeleteNodeWithView) {
 
   // Delete 3.
   {
-    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 3), 4));
+    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 3)));
 
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("NodeDeleted change_id=4 node=1,3", changes[0]);
+    EXPECT_EQ("NodeDeleted node=1,3", changes[0]);
   }
 }
 
@@ -1113,14 +999,14 @@ TEST_F(ViewManagerTest, GetNodeTree) {
 
   // Create 11 in first connection and make it a child of 1.
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 11)));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 2));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 11), 3));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 11)));
 
   // Create two nodes in second connection, 2 and 3, both children of 1.
   ASSERT_TRUE(connection2_->CreateNode(BuildNodeId(2, 2)));
   ASSERT_TRUE(connection2_->CreateNode(BuildNodeId(2, 3)));
-  ASSERT_TRUE(connection2_->AddNode(BuildNodeId(1, 1), BuildNodeId(2, 2), 4));
-  ASSERT_TRUE(connection2_->AddNode(BuildNodeId(1, 1), BuildNodeId(2, 3), 5));
+  ASSERT_TRUE(connection2_->AddNode(BuildNodeId(1, 1), BuildNodeId(2, 2)));
+  ASSERT_TRUE(connection2_->AddNode(BuildNodeId(1, 1), BuildNodeId(2, 3)));
 
   // Attach view to node 11 in the first connection.
   ASSERT_TRUE(connection_->CreateView(BuildViewId(1, 51)));
@@ -1159,7 +1045,7 @@ TEST_F(ViewManagerTest, GetNodeTree) {
 
 TEST_F(ViewManagerTest, SetNodeBounds) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 1)));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
@@ -1186,7 +1072,7 @@ TEST_F(ViewManagerTest, SetRoots) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 3)));
 
   // Parent 1 to the root.
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
 
   // Establish the second connection with roots 1 and 3.
   {
@@ -1201,48 +1087,37 @@ TEST_F(ViewManagerTest, SetRoots) {
               ChangeNodeDescription(connection2_->changes()));
   }
 
-  // Create 4 and add it to the root, connection 2 should only get id advanced.
+  // Create 4 and add it to the root, connection 2 should not getting anything.
   {
     ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 4)));
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 4), 4));
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 5", changes[0]);
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 4)));
   }
 
   // Move 4 under 3, this should expose 4 to the client.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 3), BuildNodeId(1, 4), 5));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 3), BuildNodeId(1, 4)));
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
     EXPECT_EQ(
-        "HierarchyChanged change_id=5 node=1,4 new_parent=1,3 "
-        "old_parent=null", changes[0]);
+        "HierarchyChanged node=1,4 new_parent=1,3 old_parent=null", changes[0]);
     EXPECT_EQ("[node=1,4 parent=1,3 view=null]",
               ChangeNodeDescription(connection2_->changes()));
   }
 
   // Move 4 under 2, since 2 isn't a root client should get a delete.
   {
-    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 4), 6));
+    ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 2), BuildNodeId(1, 4)));
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("NodeDeleted change_id=6 node=1,4", changes[0]);
+    EXPECT_EQ("NodeDeleted node=1,4", changes[0]);
   }
 
   // Delete 4, client shouldn't receive a delete since it should no longer know
   // about 4.
   {
-    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 4), 7));
-
-    connection2_->DoRunLoopUntilChangesCount(1);
-    const Changes changes(ChangesToDescription1(connection2_->changes()));
-    ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("ServerChangeIdAdvanced 8", changes[0]);
+    ASSERT_TRUE(connection_->DeleteNode(BuildNodeId(1, 4)));
   }
 }
 
@@ -1256,11 +1131,11 @@ TEST_F(ViewManagerTest, CantMoveNodesFromOtherRoot) {
 
   // Try to move 2 to be a child of 1 from connection 2. This should fail as 2
   // should not be able to access 1.
-  ASSERT_FALSE(connection2_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 1));
+  ASSERT_FALSE(connection2_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
 
   // Try to reparent 1 to the root. A connection is not allowed to reparent its
   // roots.
-  ASSERT_FALSE(connection2_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
+  ASSERT_FALSE(connection2_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
 }
 
 // Verify RemoveNodeFromParent fails for nodes that are descendants of the
@@ -1270,24 +1145,24 @@ TEST_F(ViewManagerTest, CantRemoveNodesInOtherRoots) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 1)));
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
 
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 2), 2));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 2)));
 
   // Establish the second connection and give it the root 1.
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
   // Connection 2 should not be able to remove node 2 or 1 from its parent.
-  ASSERT_FALSE(connection2_->RemoveNodeFromParent(BuildNodeId(1, 2), 4));
-  ASSERT_FALSE(connection2_->RemoveNodeFromParent(BuildNodeId(1, 1), 4));
+  ASSERT_FALSE(connection2_->RemoveNodeFromParent(BuildNodeId(1, 2)));
+  ASSERT_FALSE(connection2_->RemoveNodeFromParent(BuildNodeId(1, 1)));
 
   // Create nodes 10 and 11 in 2.
   ASSERT_TRUE(connection2_->CreateNode(BuildNodeId(2, 10)));
   ASSERT_TRUE(connection2_->CreateNode(BuildNodeId(2, 11)));
 
   // Parent 11 to 10.
-  ASSERT_TRUE(connection2_->AddNode(BuildNodeId(2, 10), BuildNodeId(2, 11), 4));
+  ASSERT_TRUE(connection2_->AddNode(BuildNodeId(2, 10), BuildNodeId(2, 11)));
   // Remove 11 from 10.
-  ASSERT_TRUE(connection2_->RemoveNodeFromParent( BuildNodeId(2, 11), 5));
+  ASSERT_TRUE(connection2_->RemoveNodeFromParent( BuildNodeId(2, 11)));
 
   // Verify nothing was actually removed.
   {
@@ -1306,8 +1181,8 @@ TEST_F(ViewManagerTest, CantRemoveSetViewInOtherRoots) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 1)));
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
 
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 2), 2));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 2)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
@@ -1326,8 +1201,8 @@ TEST_F(ViewManagerTest, CantGetNodeTreeOfOtherRoots) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 1)));
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
 
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1), 1));
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 2), 2));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 1)));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(0, 1), BuildNodeId(1, 2)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
@@ -1351,15 +1226,13 @@ TEST_F(ViewManagerTest, ConnectTwice) {
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 1)));
   ASSERT_TRUE(connection_->CreateNode(BuildNodeId(1, 2)));
 
-  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2), 1));
+  ASSERT_TRUE(connection_->AddNode(BuildNodeId(1, 1), BuildNodeId(1, 2)));
 
   ASSERT_NO_FATAL_FAILURE(EstablishSecondConnection(false));
 
   // Try to connect again to 1,1, this should fail as already connected to that
   // root.
-  {
-    ASSERT_FALSE(connection_->Embed(BuildNodeId(1, 1), kTestServiceURL));
-  }
+  ASSERT_FALSE(connection_->Embed(BuildNodeId(1, 1), kTestServiceURL));
 
   // Connecting to 1,2 should succeed and end up in connection2.
   {
@@ -1414,7 +1287,7 @@ TEST_F(ViewManagerTest, EmbedWithSameNodeId) {
     connection2_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection2_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ("NodeDeleted change_id=2 node=1,1", changes[0]);
+    EXPECT_EQ("NodeDeleted node=1,1", changes[0]);
   }
 
   // Connection2 has no root. Verify it can't see node 1,1 anymore.
@@ -1448,22 +1321,17 @@ TEST_F(ViewManagerTest, EmbedWithSameNodeId2) {
 
   // Create a node in the third connection and parent it to the root.
   ASSERT_TRUE(connection3->CreateNode(BuildNodeId(3, 1)));
-  ASSERT_TRUE(connection3->AddNode(BuildNodeId(1, 1), BuildNodeId(3, 1), 3));
+  ASSERT_TRUE(connection3->AddNode(BuildNodeId(1, 1), BuildNodeId(3, 1)));
 
   // Connection 1 should have been told about the add (it owns the node).
   {
     connection_->DoRunLoopUntilChangesCount(1);
     const Changes changes(ChangesToDescription1(connection_->changes()));
     ASSERT_EQ(1u, changes.size());
-    EXPECT_EQ(
-        "HierarchyChanged change_id=3 node=3,1 new_parent=1,1 old_parent=null",
-        changes[0]);
+    EXPECT_EQ("HierarchyChanged node=3,1 new_parent=1,1 old_parent=null",
+              changes[0]);
   }
 
-  // connection2_ should get an advance.
-  connection2_->DoRunLoopUntilChangesCount(1);
-  connection2_->ClearChanges();
-
   // Embed 1,1 back in connection 2.
   {
     // 2 should be told about the new embed.
@@ -1478,7 +1346,7 @@ TEST_F(ViewManagerTest, EmbedWithSameNodeId2) {
     // And 3 should get a delete.
     connection3->DoRunLoopUntilChangesCount(1);
     ASSERT_EQ(1u, connection3->changes().size());
-    EXPECT_EQ("NodeDeleted change_id=4 node=1,1",
+    EXPECT_EQ("NodeDeleted node=1,1",
               ChangesToDescription1(connection3->changes())[0]);
   }
 
@@ -1510,7 +1378,7 @@ TEST_F(ViewManagerTest, EmbedWithSameNodeId2) {
 }
 
 // TODO(sky): add coverage of test that destroys connections and ensures other
-// connections get deletion notification (or advanced server id).
+// connections get deletion notification.
 
 // TODO(sky): need to better track changes to initial connection. For example,
 // that SetBounsdNodes/AddNode and the like don't result in messages to the