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..b40022d6d266987b0ab228c5bef16f653d9933af
--- /dev/null
+++ b/ppapi/utility/threading/simple_thread.h
@@ -0,0 +1,57 @@
+// 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 that creates and runs a
+// PPAPI message loop on that thread.

[bbudge, 2012/01/10 19:40:20]

Comment doesn't seem right in the Windows case.

+class SimpleThread {
+ public:
+#ifdef WIN32

[bbudge, 2012/01/10 19:40:20]

Is WIN32 our define for Windows in general?

[brettw, 2012/01/18 17:53:09]

I think for the wrappers this is the best thing. For Chrome code there is OS_WIN
we should use instead, but this needs to be compilable by end-users.

+  typedef HANDLE ThreadHandle;
+#else
+  typedef pthread_t ThreadHandle;
+#endif
+
+  typedef void (*ThreadFunc)(MessageLoop_Dev&, void* user_data);
+
+  SimpleThread(Instance* instance);
+  ~SimpleThread();
+
+  bool Start();
+  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

[bbudge, 2012/01/10 19:40:20]

period (.)
Also, you should probably document that 'func' can be NULL and why you would
want to do that. Alternatively, ASSERT if NULL is passed.

+  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_
+