Allow p2p UDP packages to set DSCP

content/browser/renderer_host/p2p/socket_host_udp.cc

Index: content/browser/renderer_host/p2p/socket_host_udp.cc
diff --git a/content/browser/renderer_host/p2p/socket_host_udp.cc b/content/browser/renderer_host/p2p/socket_host_udp.cc
index 54c2b4cd4edba8b64435ce5a1990ba390916d1ba..0a92c1ea8c72aa2824e63b077f5b081cd8ec48f9 100644
--- a/content/browser/renderer_host/p2p/socket_host_udp.cc
+++ b/content/browser/renderer_host/p2p/socket_host_udp.cc
@@ -51,11 +51,15 @@ uint64 GetUniqueEventId(const content::P2PSocketHostUdp* obj,
 namespace content {
 
 P2PSocketHostUdp::PendingPacket::PendingPacket(
-    const net::IPEndPoint& to, const std::vector<char>& content, uint64 id)
+    const net::IPEndPoint& to,
+    const std::vector<char>& content,
+    uint64 id,
+    net::DiffServCodePoint dscp_)
     : to(to),
       data(new net::IOBuffer(content.size())),
       size(content.size()),
-      id(id) {
+      id(id),
+      dscp(dscp_) {
   memcpy(data->data(), &content[0], size);
 }
 
@@ -69,7 +73,8 @@ P2PSocketHostUdp::P2PSocketHostUdp(IPC::Sender* message_sender,
       socket_(new net::UDPServerSocket(NULL, net::NetLog::Source())),
       send_pending_(false),
       send_packet_count_(0),
-      throttler_(throttler) {
+      throttler_(throttler),
+      last_dscp_(net::DSCP_CS0) {
 }
 
 P2PSocketHostUdp::~P2PSocketHostUdp() {
@@ -168,7 +173,8 @@ void P2PSocketHostUdp::HandleReadResult(int result) {
 }
 
 void P2PSocketHostUdp::Send(const net::IPEndPoint& to,
-                            const std::vector<char>& data) {
+                            const std::vector<char>& data,
+                            net::DiffServCodePoint dscp) {
   if (!socket_) {
     // The Send message may be sent after the an OnError message was
     // sent by hasn't been processed the renderer.
@@ -193,9 +199,9 @@ void P2PSocketHostUdp::Send(const net::IPEndPoint& to,
   }
 
   if (send_pending_) {
-    send_queue_.push_back(PendingPacket(to, data, send_packet_count_));
+    send_queue_.push_back(PendingPacket(to, data, send_packet_count_, dscp));
   } else {
-    PendingPacket packet(to, data, send_packet_count_);
+    PendingPacket packet(to, data, send_packet_count_, dscp);
     DoSend(packet);
   }
   ++send_packet_count_;
@@ -205,6 +211,17 @@ void P2PSocketHostUdp::DoSend(const PendingPacket& packet) {
   TRACE_EVENT_ASYNC_BEGIN1("p2p", "Udp::DoSend",
                            GetUniqueEventId(this, packet.id),
                            "size", packet.size);
+  if (last_dscp_ != packet.dscp && last_dscp_ != net::DSCP_NO_CHANGE) {
+    int result = socket_->SetDiffServCodePoint(packet.dscp);
+    if (result == net::OK) {
+      last_dscp_ = packet.dscp;
+    } else if (!IsTransientError(result) && last_dscp_ != net::DSCP_CS0) {
+      // We receieved a non-transient error, and it seems we have
+      // not changed the DSCP in the past, disable DSCP as it unlikely
+      // to work in the future.
+      last_dscp_ = net::DSCP_NO_CHANGE;
+    }
+  }
   int result = socket_->SendTo(
       packet.data.get(),
       packet.size,