Implement the file chooser as a new resource "host"

ppapi/host/ppapi_host.h

Index: ppapi/host/ppapi_host.h
diff --git a/ppapi/host/ppapi_host.h b/ppapi/host/ppapi_host.h
new file mode 100644
index 0000000000000000000000000000000000000000..b5e95df39a699d415ee2825dd239b90677133eb2
--- /dev/null
+++ b/ppapi/host/ppapi_host.h
@@ -0,0 +1,75 @@
+// 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_PPAPI_HOST_H_
+#define PPAPI_HOST_PPAPI_HOST_H_
+
+#include <map>
+
+#include "base/memory/linked_ptr.h"
+#include "ipc/ipc_channel.h"
+#include "ipc/ipc_message.h"
+#include "ppapi/c/pp_instance.h"
+#include "ppapi/c/pp_resource.h"
+#include "ppapi/host/ppapi_host_export.h"
+
+namespace ppapi {
+
+namespace proxy {
+class ResourceMessageCallParams;
+class ResourceMessageReplyParams;
+}
+
+namespace host {
+
+class HostFactory;
+class ResourceHost;
+
+class PPAPI_HOST_EXPORT PpapiHost
+    : public IPC::Message::Sender,
+      public IPC::Channel::Listener {
+ public:
+  PpapiHost(IPC::Message::Sender* sender,
+            HostFactory* host_factory);
+  ~PpapiHost();
+
+  // Sender implementation
+  virtual bool Send(IPC::Message* msg) OVERRIDE;
+
+  // Listener implementation
+  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
+
+  void SendReply(const proxy::ResourceMessageReplyParams& params,
+                 const IPC::Message& msg);
+
+ private:
+  struct InstanceData;
+
+  // Message handlers.
+  void OnHostMsgResourceCall(const proxy::ResourceMessageCallParams& params,
+                             const IPC::Message& nested_msg);
+  void OnHostMsgResourceCreated(const proxy::ResourceMessageCallParams& param,
+                                PP_Instance instance,
+                                const IPC::Message& nested_msg);
+  void OnHostMsgResourceDestroyed(PP_Resource resource);
+
+  // Returns null if the resource doesn't exist.
+  host::ResourceHost* GetResourceHost(PP_Resource resource);
+
+  // Non-owning pointer.
+  IPC::Message::Sender* sender_;
+
+  // Non-owning pointer.
+  HostFactory* host_factory_;
+
+  typedef std::map<PP_Resource, linked_ptr<ResourceHost> > ResourceMap;
+  ResourceMap resources_;
+
+  DISALLOW_COPY_AND_ASSIGN(PpapiHost);
+};
+
+}  // namespace host
+}  // namespace ppapi
+
+#endif  // PPAPI_HOST_PPAPIE_HOST_H_