Create a PPAPI host for new resource message routing.

ppapi/host/host_factory.h

+// 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;
+
+// A host factory creates ResourceHosts for incoming create messages from
+// the plugin. This allows us to implement the hosts at the chrome/content
+// layer without the ppapi layer knowing about the details.
+class HostFactory {
+ public:
+  virtual scoped_ptr<ResourceHost> CreateMessageReceived(

[dmichael (off chromium), 2012/06/22 16:56:49]

The name's slightly confusing, seeing as this is a factory and it's creating a
ResourceHost. It could be CreateResourceHost, since that's what it does.

(An alternate could be "DidReceiveCreateMessage", but this class doesn't really
need to know or care *why* it's creating a ResourceHost.)

+      PpapiHost* host,
+      const proxy::ResourceMessageCallParams& params,
+      PP_Instance instance,
+      const IPC::Message& message) = 0;
+
+ protected:
+  virtual ~HostFactory() {}

[dmichael (off chromium), 2012/06/22 16:56:49]

Is it important that we disallow deleting via a base pointer? I don't think
there's an advantage to making the destructor protected.

+};
+
+}  // namespace host
+}  // namespace ppapi
+
+#endif  // PPAPI_HOST_HOST_FACTORY_H_