Revert of Move content's shell connections to the IO thread

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index cfb6278ba29b5091ec26eb9e5a6b4f3a7c1df5b9..304c589e7c69caf194802ab4eaaeb0913aafa6e7 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -142,8 +142,6 @@
 #include "net/base/port_util.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
 #include "net/base/url_util.h"
-#include "services/shell/public/cpp/interface_provider.h"
-#include "services/shell/public/cpp/interface_registry.h"
 #include "skia/ext/event_tracer_impl.h"
 #include "skia/ext/skia_memory_dump_provider.h"
 #include "third_party/WebKit/public/platform/WebImageGenerator.h"
@@ -842,6 +840,15 @@
   GetInterfaceRegistry()->AddInterface(base::Bind(CreateFrameFactory));
   GetInterfaceRegistry()->AddInterface(base::Bind(CreateEmbeddedWorkerSetup));
 
+#if defined(MOJO_SHELL_CLIENT) && defined(USE_AURA)
+  // We may not have a MojoShellConnection object in tests that directly
+  // instantiate a RenderThreadImpl.
+  if (MojoShellConnection::GetForProcess() &&
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kUseMusInRenderer))
+    CreateRenderWidgetWindowTreeClientFactory();
+#endif
+
   GetRemoteInterfaces()->GetInterface(
       mojo::GetProxy(&storage_partition_service_));
 
@@ -976,15 +983,6 @@
   main_message_loop_.reset();
 
   lazy_tls.Pointer()->Set(NULL);
-}
-
-void RenderThreadImpl::AddConnectionFilters(MojoShellConnection* connection) {
-#if defined(MOJO_SHELL_CLIENT) && defined(USE_AURA)
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kUseMusInRenderer)) {
-    CreateRenderWidgetWindowTreeClientFactory(connection);
-  }
-#endif
 }
 
 bool RenderThreadImpl::Send(IPC::Message* msg) {