Start of adding enums for error codes

mojo/services/view_manager/view_manager_service_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/services/view_manager/view_manager_service_impl.h"
 
 #include "base/bind.h"
 #include "mojo/services/public/cpp/geometry/geometry_type_converters.h"
 #include "mojo/services/public/cpp/input_events/input_events_type_converters.h"
 #include "mojo/services/view_manager/node.h"
@@ skipping 524 matching lines @@
     inode->view_id =
         ViewIdToTransportId(node->view() ? node->view()->id() : ViewId());
     inode->bounds = Rect::From(node->bounds());
     array[i] = inode.Pass();
   }
   return array.Pass();
 }
 
 void ViewManagerServiceImpl::CreateNode(
     Id transport_node_id,
-    const Callback<void(bool)>& callback) {
+    const Callback<void(ErrorCode)>& callback) {
   const NodeId node_id(NodeIdFromTransportId(transport_node_id));
-  if (node_id.connection_id != id_ ||
-      node_map_.find(node_id.node_id) != node_map_.end()) {
-    callback.Run(false);
-    return;
+  ErrorCode error_code = ERROR_CODE_NONE;
+  if (node_id.connection_id != id_) {
+    error_code = ERROR_CODE_ILLEGAL_ARGUMENT;
+  } else if (node_map_.find(node_id.node_id) != node_map_.end()) {
+    error_code = ERROR_CODE_VALUE_IN_USE;
+  } else {
+    node_map_[node_id.node_id] = new Node(root_node_manager_, node_id);
+    known_nodes_.insert(transport_node_id);
   }
-  node_map_[node_id.node_id] = new Node(root_node_manager_, node_id);
-  known_nodes_.insert(transport_node_id);
-  callback.Run(true);
+  callback.Run(error_code);
 }
 
 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)) {
@@ skipping 230 matching lines @@
   client()->OnViewManagerConnectionEstablished(
       id_,
       creator_url_,
       root_node_manager_->next_server_change_id(),
       NodesToNodeDatas(to_send));
 }
 
 }  // namespace service
 }  // namespace view_manager
 }  // namespace mojo