Set up content in-process main threads via factory

content/gpu/gpu_main_thread.h

Index: content/gpu/gpu_main_thread.h
diff --git a/content/gpu/gpu_main_thread.h b/content/gpu/gpu_main_thread.h
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index 0000000000000000000000000000000000000000..f34f43183ae7786829a896ead41922cff5a42ead
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+++ b/content/gpu/gpu_main_thread.h
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+// 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_GPU_GPU_MAIN_THREAD_H_
+#define CONTENT_GPU_GPU_MAIN_THREAD_H_
+
+#include "base/threading/thread.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class GpuProcess;
+
+// This class creates a GPU thread (instead of a GPU process), when running
+// with --in-process-gpu or --single-process.
+class GpuMainThread : public base::Thread {
+ public:
+  explicit GpuMainThread(const std::string& channel_id);
+  virtual ~GpuMainThread();
+
+ protected:
+  virtual void Init() OVERRIDE;
+  virtual void CleanUp() OVERRIDE;
+
+ private:
+  std::string channel_id_;
+  // Deleted in CleanUp() on the gpu thread, so don't use smart pointers.
+  GpuProcess* gpu_process_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuMainThread);
+};
+
+CONTENT_EXPORT base::Thread* CreateGpuMainThread(const std::string& channel_id);
+
+}  // namespace content
+
+#endif  // CONTENT_GPU_GPU_MAIN_THREAD_H_