mus: Fix creating the factory for window-tree-client in renderer.

content/renderer/mus/renderer_window_tree_client.cc

 // Copyright 2017 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 "content/renderer/mus/renderer_window_tree_client.h"
 
 #include <map>
 
 #include "base/lazy_instance.h"
 #include "services/ui/public/cpp/window_compositor_frame_sink.h"
 
 namespace content {
 
 namespace {
 typedef std::map<int, RendererWindowTreeClient*> ConnectionMap;
 base::LazyInstance<ConnectionMap>::Leaky g_connections =
     LAZY_INSTANCE_INITIALIZER;
 }  // namespace
 
 // static
 RendererWindowTreeClient* RendererWindowTreeClient::Get(int routing_id) {
   auto it = g_connections.Get().find(routing_id);
   if (it != g_connections.Get().end())
     return it->second;
   return nullptr;
 }
 
 // static
-void RendererWindowTreeClient::Create(int routing_id) {
-  DCHECK(g_connections.Get().find(routing_id) == g_connections.Get().end())
-      << routing_id;
+void RendererWindowTreeClient::CreateIfNecessary(int routing_id) {
+  if (Get(routing_id))
+    return;
   RendererWindowTreeClient* connection =
       new RendererWindowTreeClient(routing_id);
   g_connections.Get().insert(std::make_pair(routing_id, connection));
 }
 
 // static
 void RendererWindowTreeClient::Destroy(int routing_id) {
   auto* client = Get(routing_id);
   if (client)
     client->DestroySelf();
@@ skipping 182 matching lines @@
                                                  bool success) {}
 
 void RendererWindowTreeClient::RequestClose(uint32_t window_id) {}
 
 void RendererWindowTreeClient::GetWindowManager(
     mojo::AssociatedInterfaceRequest<ui::mojom::WindowManager> internal) {
   NOTREACHED();
 }
 
 }  // namespace content