First pass at implementing the MessageLoop interface. This includes a simple

ppapi/utility/threading/simple_thread.h

Index: ppapi/utility/threading/simple_thread.h
diff --git a/ppapi/utility/threading/simple_thread.h b/ppapi/utility/threading/simple_thread.h
new file mode 100644
index 0000000000000000000000000000000000000000..a093961bf539fbe45715035969bd51351dc83ab1
--- /dev/null
+++ b/ppapi/utility/threading/simple_thread.h
@@ -0,0 +1,65 @@
+// 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.
+
+#ifndef PPAPI_UTILITY_THREADING_SIMPLE_THREAD_H_
+#define PPAPI_UTILITY_THREADING_SIMPLE_THREAD_H_
+
+#ifdef WIN32
+#include <windows.h>
+#else
+#include <pthread.h>
+#endif
+
+#include "ppapi/cpp/dev/message_loop_dev.h"
+
+namespace pp {
+
+// This class is a simple wrapper around a pthread/Windows thread that creates
+// and runs a PPAPI message loop on that thread.
+class SimpleThread {
+ public:
+#ifdef WIN32
+  typedef HANDLE ThreadHandle;
+#else
+  typedef pthread_t ThreadHandle;
+#endif
+
+  typedef void (*ThreadFunc)(MessageLoop_Dev&, void* user_data);
+
+  SimpleThread(Instance* instance);
+  ~SimpleThread();
+
+  // Starts a thread and runs a message loop in it. If you need control over
+  // how the message loop is run, use StartWithFunction. Returns true on
+  // success, false if the thread is already running or couldn't be started.
+  bool Start();
+
+  // Posts a quit message to the message loop and blocks until the thread
+  // exits. Returns true on success. If the thread is not running, returns
+  // false.
+  bool Join();
+
+  // Normally you can just use Start() to start a thread, and then post work to
+  // it. In some cases you will want control over the message. If ThreadFunc
+  // is NULL, this acts the same as Start().
+  bool StartWithFunction(ThreadFunc func, void* user_data);
+
+  MessageLoop_Dev& message_loop() { return message_loop_; }
+  ThreadHandle thread() const { return thread_; }
+
+ private:
+  Instance* instance_;
+  MessageLoop_Dev message_loop_;
+
+  ThreadHandle thread_;
+
+  // Disallow (not implemented).
+  SimpleThread(const SimpleThread&);
+  SimpleThread& operator=(const SimpleThread&);
+};
+
+}  // namespace pp
+
+#endif  // PPAPI_UTILITY_THREADING_SIMPLE_THREAD_H_
+