Implement the file chooser as a new resource "host"

ppapi/host/host_factory.h

Index: ppapi/host/host_factory.h
diff --git a/ppapi/host/host_factory.h b/ppapi/host/host_factory.h
new file mode 100644
index 0000000000000000000000000000000000000000..9dafb035ce21986f3226ee6d400806db8d7e0102
--- /dev/null
+++ b/ppapi/host/host_factory.h
@@ -0,0 +1,41 @@
+// 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_HOST_HOST_FACTORY_H_
+#define PPAPI_HOST_HOST_FACTORY_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "ppapi/c/pp_instance.h"
+
+namespace IPC {
+class Message;
+}
+
+namespace ppapi {
+
+namespace proxy {
+class ResourceMessageCallParams;
+}
+
+namespace host {
+
+class PpapiHost;
+class ResourceHost;
+
+class HostFactory {
+ public:
+  virtual scoped_ptr<ResourceHost> CreateMessageReceived(
+      PpapiHost* host,
+      const proxy::ResourceMessageCallParams& params,
+      PP_Instance instance,
+      const IPC::Message& message) = 0;
+
+ protected:
+  virtual ~HostFactory() {}
+};
+
+}  // namespace host
+}  // namespace ppapi
+
+#endif  // PPAPI_HOST_HOST_FACTORY_H_