Fix a QUIC bug in which PING frames were not being ACK'd.

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index ab1e0fe8de4158f8b83c41e962a17843d4154a26..a9ad334afa64dafb62b1afc9d5d72aae029e8380 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -300,13 +300,15 @@ void QuicConnection::OnError(QuicFramer* framer) {
 
 void QuicConnection::OnPacket() {
   DCHECK(last_stream_frames_.empty() &&
+         last_ack_frames_.empty() &&
+         last_congestion_frames_.empty() &&
+         last_stop_waiting_frames_.empty() &&
+         last_rst_frames_.empty() &&
          last_goaway_frames_.empty() &&
          last_window_update_frames_.empty() &&
          last_blocked_frames_.empty() &&
-         last_rst_frames_.empty() &&
-         last_ack_frames_.empty() &&
-         last_congestion_frames_.empty() &&
-         last_stop_waiting_frames_.empty());
+         last_ping_frames_.empty() &&
+         last_close_frames_.empty());
 }
 
 void QuicConnection::OnPublicResetPacket(
@@ -617,6 +619,7 @@ bool QuicConnection::OnPingFrame(const QuicPingFrame& frame) {
   if (debug_visitor_.get() != NULL) {
     debug_visitor_->OnPingFrame(frame);
   }
+  last_ping_frames_.push_back(frame);
   return true;
 }
 
@@ -778,17 +781,17 @@ void QuicConnection::OnPacketComplete() {
 
   DVLOG(1) << ENDPOINT << (last_packet_revived_ ? "Revived" : "Got")
            << " packet " << last_header_.packet_sequence_number
-           << " with " << last_ack_frames_.size() << " acks, "
+           << " with " << last_stream_frames_.size()<< " stream frames "
+           << last_ack_frames_.size() << " acks, "
            << last_congestion_frames_.size() << " congestions, "
            << last_stop_waiting_frames_.size() << " stop_waiting, "
+           << last_rst_frames_.size() << " rsts, "
            << last_goaway_frames_.size() << " goaways, "
            << last_window_update_frames_.size() << " window updates, "
            << last_blocked_frames_.size() << " blocked, "
-           << last_rst_frames_.size() << " rsts, "
+           << last_ping_frames_.size() << " pings, "
            << last_close_frames_.size() << " closes, "
-           << last_stream_frames_.size()
-           << " stream frames for "
-           << last_header_.public_header.connection_id;
+           << "for " << last_header_.public_header.connection_id;
 
   // Call MaybeQueueAck() before recording the received packet, since we want
   // to trigger an ack if the newly received packet was previously missing.
@@ -881,13 +884,15 @@ void QuicConnection::MaybeQueueAck() {
 
 void QuicConnection::ClearLastFrames() {
   last_stream_frames_.clear();
+  last_ack_frames_.clear();
+  last_congestion_frames_.clear();
+  last_stop_waiting_frames_.clear();
+  last_rst_frames_.clear();
   last_goaway_frames_.clear();
   last_window_update_frames_.clear();
   last_blocked_frames_.clear();
-  last_rst_frames_.clear();
-  last_ack_frames_.clear();
-  last_stop_waiting_frames_.clear();
-  last_congestion_frames_.clear();
+  last_ping_frames_.clear();
+  last_close_frames_.clear();
 }
 
 QuicAckFrame* QuicConnection::CreateAckFrame() {
@@ -913,7 +918,8 @@ bool QuicConnection::ShouldLastPacketInstigateAck() const {
       !last_goaway_frames_.empty() ||
       !last_rst_frames_.empty() ||
       !last_window_update_frames_.empty() ||
-      !last_blocked_frames_.empty()) {
+      !last_blocked_frames_.empty() ||
+      !last_ping_frames_.empty()) {
     return true;
   }