Add an asynchronous version of the Flash DeviceID API.

ppapi/thunk/ppb_flash_device_id_api.h

Index: ppapi/thunk/ppb_flash_device_id_api.h
diff --git a/ppapi/thunk/ppb_flash_device_id_api.h b/ppapi/thunk/ppb_flash_device_id_api.h
new file mode 100644
index 0000000000000000000000000000000000000000..ae31abd33e84957cdd85f8b3a19f93e3f150cdbe
--- /dev/null
+++ b/ppapi/thunk/ppb_flash_device_id_api.h
@@ -0,0 +1,18 @@
+// 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.
+
+namespace ppapi {
+namespace thunk {
+
+class PPAPI_THUNK_EXPORT PPB_Flash_DeviceID_API {
+ public:
+  virtual ~PPB_Flash_DeviceID_API() {}
+
+  virtual int32_t GetDeviceID(PP_Var* id,
+                              const PP_CompletionCallback& callback) = 0;
+};
+
+}  // namespace thunk
+}  // namespace ppapi
+