Add a new SpdyStream::Delegate method to handle trailers

net/spdy/spdy_stream.cc

Index: net/spdy/spdy_stream.cc
diff --git a/net/spdy/spdy_stream.cc b/net/spdy/spdy_stream.cc
index a78a78f790f4bfda1fe43cbb2704fd4d118894b3..f2502a6b2597b4ac0d274c2e49a689d800340774 100644
--- a/net/spdy/spdy_stream.cc
+++ b/net/spdy/spdy_stream.cc
@@ -57,6 +57,8 @@ bool ContainsUppercaseAscii(const std::string& str) {
 
 }  // namespace
 
+void SpdyStream::Delegate::OnTrailers(const SpdyHeaderBlock& trailers) {}
+
 // A wrapper around a stream that calls into ProduceSynStreamFrame().
 class SpdyStream::SynStreamBufferProducer : public SpdyBufferProducer {
  public:
@@ -440,12 +442,18 @@ int SpdyStream::OnInitialResponseHeadersReceived(
 int SpdyStream::OnAdditionalResponseHeadersReceived(
     const SpdyHeaderBlock& additional_response_headers) {
   if (type_ == SPDY_REQUEST_RESPONSE_STREAM) {
-    session_->ResetStream(
-        stream_id_, RST_STREAM_PROTOCOL_ERROR,
-        "Additional headers received for request/response stream");
-    return ERR_SPDY_PROTOCOL_ERROR;
-  } else if (type_ == SPDY_PUSH_STREAM &&
-             response_headers_status_ == RESPONSE_HEADERS_ARE_COMPLETE) {
+    if (response_headers_status_ != RESPONSE_HEADERS_ARE_COMPLETE) {
+      session_->ResetStream(
+          stream_id_, RST_STREAM_PROTOCOL_ERROR,
+          "Additional headers received for request/response stream");
+      return ERR_SPDY_PROTOCOL_ERROR;
+    }
+    response_headers_status_ = TRAILERS_RECEIVED;
+    delegate_->OnTrailers(additional_response_headers);
+    return OK;
+  }
+  if (type_ == SPDY_PUSH_STREAM &&
+      response_headers_status_ == RESPONSE_HEADERS_ARE_COMPLETE) {
     session_->ResetStream(
         stream_id_, RST_STREAM_PROTOCOL_ERROR,
         "Additional headers received for push stream");