Set up content in-process main threads via factory

content/renderer/renderer_main_thread.h

Index: content/renderer/renderer_main_thread.h
diff --git a/content/renderer/renderer_main_thread.h b/content/renderer/renderer_main_thread.h
new file mode 100644
index 0000000000000000000000000000000000000000..dca7cb81fb28325d30ff87895e73c1ea59c28173
--- /dev/null
+++ b/content/renderer/renderer_main_thread.h
@@ -0,0 +1,39 @@
+// Copyright 2013 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.
+
+#ifndef CONTENT_RENDERER_RENDERER_MAIN_THREAD_H_
+#define CONTENT_RENDERER_RENDERER_MAIN_THREAD_H_
+
+#include <string>
+
+#include "base/threading/thread.h"
+#include "content/common/content_export.h"
+
+namespace content {
+class RenderProcess;
+
+// This class creates the IO thread for the renderer when running in
+// single-process mode.  It's not used in multi-process mode.
+class RendererMainThread : public base::Thread {
+ public:
+  explicit RendererMainThread(const std::string& channel_id);
+  virtual ~RendererMainThread();
+
+ protected:
+  virtual void Init() OVERRIDE;
+  virtual void CleanUp() OVERRIDE;
+
+ private:
+  std::string channel_id_;
+  scoped_ptr<RenderProcess> render_process_;
+
+  DISALLOW_COPY_AND_ASSIGN(RendererMainThread);
+};
+
+CONTENT_EXPORT base::Thread* CreateRendererMainThread(
+    const std::string& channel_id);
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_RENDERER_MAIN_THREAD_H_