Hook embedded shell up to MojoShellConnection

content/renderer/render_thread_impl.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_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <utility>
@@ skipping 842 matching lines @@
       ChildThreadImpl::discardable_shared_memory_manager());
 
   service_registry()->AddService<RenderFrameSetup>(
       base::Bind(CreateRenderFrameSetup));
   service_registry()->AddService<EmbeddedWorkerSetup>(
       base::Bind(CreateEmbeddedWorkerSetup));
 
 #if defined(MOJO_SHELL_CLIENT)
   // We may not have a MojoShellConnection object in tests that directly
   // instantiate a RenderThreadImpl.
-  if (MojoShellConnection::Get())
+  if (MojoShellConnection::Get() &&
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseMusInRenderer))
     CreateRenderWidgetWindowTreeClientFactory();
 #endif
 }
 
 RenderThreadImpl::~RenderThreadImpl() {
 }
 
 void RenderThreadImpl::Shutdown() {
   FOR_EACH_OBSERVER(
       RenderProcessObserver, observers_, OnRenderProcessShutdown());
@@ skipping 1303 matching lines @@
 }
 
 void RenderThreadImpl::PendingRenderFrameConnect::OnConnectionError() {
   size_t erased =
       RenderThreadImpl::current()->pending_render_frame_connects_.erase(
           routing_id_);
   DCHECK_EQ(1u, erased);
 }
 
 }  // namespace content