Move content's shell connections to the IO thread

content/renderer/mus/render_widget_window_tree_client_factory.cc

Index: content/renderer/mus/render_widget_window_tree_client_factory.cc
diff --git a/content/renderer/mus/render_widget_window_tree_client_factory.cc b/content/renderer/mus/render_widget_window_tree_client_factory.cc
index 5abfc23f4c02e40bed6e8a29b965f1eb065e531b..a52d32cf37a3b0e48f61362079e6959af5101341 100644
--- a/content/renderer/mus/render_widget_window_tree_client_factory.cc
+++ b/content/renderer/mus/render_widget_window_tree_client_factory.cc
@@ -9,12 +9,14 @@
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "content/common/render_widget_window_tree_client_factory.mojom.h"
-#include "content/public/child/child_thread.h"
+#include "content/public/common/connection_filter.h"
 #include "content/public/common/mojo_shell_connection.h"
 #include "content/renderer/mus/render_widget_mus_connection.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
-#include "services/shell/public/cpp/connection.h"
 #include "services/shell/public/cpp/interface_factory.h"
 #include "services/shell/public/cpp/service.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
@@ -24,23 +26,32 @@ namespace content {
 
 namespace {
 
+void BindMusConnectionOnMainThread(
+    uint32_t routing_id,
+    ui::mojom::WindowTreeClientRequest request) {
+  RenderWidgetMusConnection* connection =
+      RenderWidgetMusConnection::GetOrCreate(routing_id);
+  connection->Bind(std::move(request));
+}
+
 // This object's lifetime is managed by MojoShellConnection because it's a
 // registered with it.
 class RenderWidgetWindowTreeClientFactoryImpl
-    : public shell::Service,
+    : public ConnectionFilter,
       public shell::InterfaceFactory<
           mojom::RenderWidgetWindowTreeClientFactory>,
       public mojom::RenderWidgetWindowTreeClientFactory {
  public:
   RenderWidgetWindowTreeClientFactoryImpl() {
-    DCHECK(ChildThread::Get()->GetMojoShellConnection());
+    main_thread_task_runner_ = base::ThreadTaskRunnerHandle::Get();
   }
 
   ~RenderWidgetWindowTreeClientFactoryImpl() override {}
 
  private:
-  // shell::Service implementation:
-  bool OnConnect(shell::Connection* connection) override {
+  // ConnectionFilter implementation:
+  bool OnConnect(shell::Connection* connection,
+                 shell::Connector* connector) override {
     connection->AddInterface<mojom::RenderWidgetWindowTreeClientFactory>(this);
     return true;
   }
@@ -55,12 +66,13 @@ class RenderWidgetWindowTreeClientFactoryImpl
   // mojom::RenderWidgetWindowTreeClientFactory implementation.
   void CreateWindowTreeClientForRenderWidget(
       uint32_t routing_id,
-      mojo::InterfaceRequest<ui::mojom::WindowTreeClient> request) override {
-    RenderWidgetMusConnection* connection =
-        RenderWidgetMusConnection::GetOrCreate(routing_id);
-    connection->Bind(std::move(request));
+      ui::mojom::WindowTreeClientRequest request) override {
+    main_thread_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&BindMusConnectionOnMainThread, routing_id,
+                              base::Passed(&request)));
   }
 
+  scoped_refptr<base::SequencedTaskRunner> main_thread_task_runner_;
   mojo::BindingSet<mojom::RenderWidgetWindowTreeClientFactory> bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetWindowTreeClientFactoryImpl);
@@ -68,9 +80,10 @@ class RenderWidgetWindowTreeClientFactoryImpl
 
 }  // namespace
 
-void CreateRenderWidgetWindowTreeClientFactory() {
-  ChildThread::Get()->GetMojoShellConnection()->MergeService(
-      base::WrapUnique(new RenderWidgetWindowTreeClientFactoryImpl));
+void CreateRenderWidgetWindowTreeClientFactory(
+    MojoShellConnection* connection) {
+  connection->AddConnectionFilter(
+      base::MakeUnique<RenderWidgetWindowTreeClientFactoryImpl>());
 }
 
 }  // namespace content