Convert the async device ID getter to a chrome resource host

ppapi/host/ppapi_host.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_PPAPI_HOST_H_
 #define PPAPI_HOST_PPAPI_HOST_H_
 
 #include <map>
 
 #include "base/compiler_specific.h"
@@ skipping 19 matching lines @@
 
 class HostFactory;
 class InstanceMessageFilter;
 class ResourceHost;
 
 // The host provides routing and tracking for resource message calls that
 // come from the plugin to the host (browser or renderer), and the
 // corresponding replies.
 class PPAPI_HOST_EXPORT PpapiHost : public IPC::Sender, public IPC::Listener {
  public:
-  // The sender is the channel to the plugin for outgoing messages. The factory
-  // will be used to receive resource creation messages from the plugin. Both
-  // pointers are owned by the caller and must outlive this class.
-  PpapiHost(IPC::Sender* sender,
-            HostFactory* host_factory,
-            const PpapiPermissions& perms);
+  // The sender is the channel to the plugin for outgoing messages.
+  // Normally the creator will add filters for resource creation messages
+  // (AddHostFactoryFilter) and instance messages (AddInstanceMessageFilter)
+  // after construction.
+  PpapiHost(IPC::Sender* sender, const PpapiPermissions& perms);
   virtual ~PpapiHost();
 
   const PpapiPermissions& permissions() const { return permissions_; }
 
   // Sender implementation. Forwards to the sender_.
   virtual bool Send(IPC::Message* msg) OVERRIDE;
 
   // Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
   // Sends the given reply message to the plugin.
   void SendReply(const proxy::ResourceMessageReplyParams& params,
                  const IPC::Message& msg);
 
+  // Adds the given host factory filter to the host. The PpapiHost will take
+  // ownership of the pointer.
+  void AddHostFactoryFilter(scoped_ptr<HostFactory> filter);
+
   // Adds the given message filter to the host. The PpapiHost will take
   // ownership of the pointer.
   void AddInstanceMessageFilter(scoped_ptr<InstanceMessageFilter> filter);
 
  private:
   friend class InstanceMessageFilter;
 
   // 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::Sender* sender_;
 
-  // Non-owning pointer.
-  HostFactory* host_factory_;
+  PpapiPermissions permissions_;
 
-  PpapiPermissions permissions_;
+  // Filters for resource creation messages. Note that since we don't support
+  // deleting these dynamically we don't need to worry about modifications
+  // during iteration. If we add that capability, this should be replaced with
+  // an ObserverList.
+  ScopedVector<HostFactory> host_factory_filters_;
 
   // Filters for instance messages. Note that since we don't support deleting
   // these dynamically we don't need to worry about modifications during
   // iteration. If we add that capability, this should be replaced with an
   // ObserverList.
   ScopedVector<InstanceMessageFilter> instance_message_filters_;
 
   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_