Minor cleanup and optimization of QuicConnection::IsConnectionClose.

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 454a15b59b5780745b593b603b0c4c06aa0d8bf2..be82bff04eb1d1a116fc1142f9d4dee580287a47 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -1403,7 +1403,8 @@ bool QuicConnection::WritePacketInner(QueuedPacket* packet) {
     return true;
   }
   // Connection close packets are encrypted and saved, so don't exit early.
-  if (writer_->IsWriteBlocked() && !IsConnectionClose(*packet)) {
+  const bool is_connection_close = IsConnectionClose(*packet);
+  if (writer_->IsWriteBlocked() && !is_connection_close) {
     return false;
   }
 
@@ -1427,7 +1428,7 @@ bool QuicConnection::WritePacketInner(QueuedPacket* packet) {
   // Connection close packets are eventually owned by TimeWaitListManager.
   // Others are deleted at the end of this call.
   scoped_ptr<QuicEncryptedPacket> encrypted_deleter;
-  if (IsConnectionClose(*packet)) {
+  if (is_connection_close) {
     DCHECK(connection_close_packet_.get() == nullptr);
     connection_close_packet_.reset(encrypted);
     // This assures we won't try to write *forced* packets when blocked.
@@ -2104,15 +2105,14 @@ HasRetransmittableData QuicConnection::IsRetransmittable(
   }
 }
 
-bool QuicConnection::IsConnectionClose(
-    QueuedPacket packet) {
-  RetransmittableFrames* retransmittable_frames =
+bool QuicConnection::IsConnectionClose(const QueuedPacket& packet) {
+  const RetransmittableFrames* retransmittable_frames =
       packet.serialized_packet.retransmittable_frames;
-  if (!retransmittable_frames) {
+  if (retransmittable_frames == nullptr) {
     return false;
   }
-  for (size_t i = 0; i < retransmittable_frames->frames().size(); ++i) {
-    if (retransmittable_frames->frames()[i].type == CONNECTION_CLOSE_FRAME) {
+  for (const QuicFrame& frame : retransmittable_frames->frames()) {
+    if (frame.type == CONNECTION_CLOSE_FRAME) {
       return true;
     }
   }