Allow EmbedRoot to be called multiple times.

mojo/services/view_manager/root_node_manager.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/root_node_manager.h"
 
 #include "base/logging.h"
 #include "mojo/public/cpp/application/application_connection.h"
 #include "mojo/public/interfaces/service_provider/service_provider.mojom.h"
 #include "mojo/services/public/cpp/input_events/input_events_type_converters.h"
@@ skipping 70 matching lines @@
   connections_created_by_connect_.erase(connection);
 
   // Notify remaining connections so that they can cleanup.
   for (ConnectionMap::const_iterator i = connection_map_.begin();
        i != connection_map_.end(); ++i) {
     i->second->OnViewManagerServiceImplDestroyed(connection->id());
   }
 }
 
 void RootNodeManager::EmbedRoot(const std::string& url) {
-  CHECK(connection_map_.empty());
-  EmbedImpl(kRootConnection, String::From(url), InvalidNodeId());
+  if (connection_map_.empty()) {
+    EmbedImpl(kRootConnection, String::From(url), InvalidNodeId());
+    return;
+  }
+  ViewManagerServiceImpl* connection = GetConnection(kWindowManagerConnection);
+  connection->client()->EmbedRoot(url);
 }
 
 void RootNodeManager::Embed(ConnectionSpecificId creator_id,
                             const String& url,
                             Id transport_node_id) {
   EmbedImpl(creator_id, url, NodeIdFromTransportId(transport_node_id))->
       set_delete_on_connection_error();
 }
 
 ViewManagerServiceImpl* RootNodeManager::GetConnection(
@@ skipping 188 matching lines @@
 }
 
 void RootNodeManager::OnViewInputEvent(const View* view,
                                        const ui::Event* event) {
   DispatchViewInputEventToWindowManager(view, event);
 }
 
 }  // namespace service
 }  // namespace view_manager
 }  // namespace mojo