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

content/renderer/render_widget.cc

 // Copyright (c) 2012 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/render_widget.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 373 matching lines @@
   // In tests there may not be a RenderThreadImpl.
   if (RenderThreadImpl::current()) {
     render_widget_scheduling_state_ = RenderThreadImpl::current()
                                           ->GetRendererScheduler()
                                           ->NewRenderWidgetSchedulingState();
     render_widget_scheduling_state_->SetHidden(is_hidden_);
   }
 #if defined(USE_AURA)
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kNoUseMusInRenderer)) {
-    RendererWindowTreeClient::Create(routing_id_);
+    RendererWindowTreeClient::CreateIfNecessary(routing_id_);
   }
 #endif
 }
 
 RenderWidget::~RenderWidget() {
   DCHECK(!webwidget_internal_) << "Leaking our WebWidget!";
 
   // If we are swapped out, we have released already.
   if (!is_swapped_out_ && RenderProcess::current())
     RenderProcess::current()->ReleaseProcess();
@@ skipping 1885 matching lines @@
     // browser side (https://crbug.com/669219).
     // If there is no WebFrameWidget, then there will be no
     // InputMethodControllers for a WebLocalFrame.
     return nullptr;
   }
   return static_cast<blink::WebFrameWidget*>(GetWebWidget())
       ->getActiveWebInputMethodController();
 }
 
 }  // namespace content