Factor out PP_FileHandle from ppb_flash_file into its

ppapi/api/private/pp_file_handle.idl

Index: ppapi/api/private/pp_file_handle.idl
diff --git a/ppapi/api/private/pp_file_handle.idl b/ppapi/api/private/pp_file_handle.idl
new file mode 100644
index 0000000000000000000000000000000000000000..07bb74b7e826c01cabef8592d578b0f8372a62bb
--- /dev/null
+++ b/ppapi/api/private/pp_file_handle.idl
@@ -0,0 +1,22 @@
+/* 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.
+ */
+
+/**
+ * This file provides support for native OS file handles.
+ */
+
+#inline c
+
+#ifdef _WIN32
+#include<windows.h>
+typedef HANDLE PP_FileHandle;
+static const PP_FileHandle PP_kInvalidFileHandle = NULL;
+
+#else
+typedef int PP_FileHandle;
+static const PP_FileHandle PP_kInvalidFileHandle = -1;
+#endif
+
+#endinl