Pepper: Allow plugins to call PPB_UDP_Socket::SendTo multiple times.

ppapi/proxy/udp_socket_resource_base.h

 // Copyright 2013 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_PROXY_UDP_SOCKET_RESOURCE_BASE_H_
 #define PPAPI_PROXY_UDP_SOCKET_RESOURCE_BASE_H_
 
 #include <queue>
 #include <string>
 
@@ skipping 27 matching lines @@
   static const int32_t kMaxSendBufferSize;
   // The maximum number that we allow for setting
   // PP_UDPSOCKET_OPTION_RECV_BUFFER_SIZE. This number is only for input
   // argument sanity check, it doesn't mean the browser guarantees to support
   // such a buffer size.
   static const int32_t kMaxReceiveBufferSize;
 
   // The maximum number of received packets that we allow instances of this
   // class to buffer.
   static const size_t kPluginReceiveBufferSlots;
+  // The maximum number of buffers that we allow instances of this class to be
+  // sending before we block the plugin.
+  static const size_t kPluginSendBufferSlots;
 
  protected:
   UDPSocketResourceBase(Connection connection,
                         PP_Instance instance,
                         bool private_api);
   virtual ~UDPSocketResourceBase();
 
   int32_t SetOptionImpl(PP_UDPSocket_Option name,
                         const PP_Var& value,
                         scoped_refptr<TrackedCallback> callback);
@@ skipping 46 matching lines @@
                             char* output_buffer,
                             int32_t num_bytes,
                             PP_Resource* output_addr);
 
   bool private_api_;
   bool bound_;
   bool closed_;
 
   scoped_refptr<TrackedCallback> bind_callback_;
   scoped_refptr<TrackedCallback> recvfrom_callback_;
-  scoped_refptr<TrackedCallback> sendto_callback_;
 
   char* read_buffer_;
   int32_t bytes_to_read_;
   PP_Resource* recvfrom_addr_resource_;
 
   PP_NetAddress_Private recvfrom_addr_;
   PP_NetAddress_Private bound_addr_;
 
   std::queue<RecvBuffer> recv_buffers_;
 
+  std::queue<scoped_refptr<TrackedCallback>> sendto_callbacks_;
+
   DISALLOW_COPY_AND_ASSIGN(UDPSocketResourceBase);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_UDP_SOCKET_RESOURCE_BASE_H_