Remove unused QuicStreamRequest::is_https_ field.

No behavior change.

BUG=none

Review URL: https://codereview.chromium.org/985403002

Cr-Commit-Position: refs/heads/master@{#319584}

net/quic/quic_stream_factory.cc

@@ -550,7 +550,6 @@ int QuicStreamRequest::Request(const HostPortPair& host_port_pair,
                             net_log, this);
   if (rv == ERR_IO_PENDING) {
     host_port_pair_ = host_port_pair;
-    is_https_ = is_https;
     net_log_ = net_log;
     callback_ = callback;
   } else {

net/quic/quic_stream_factory.h

@@ -75,7 +75,6 @@ class NET_EXPORT_PRIVATE QuicStreamRequest {
  private:
   QuicStreamFactory* factory_;
   HostPortPair host_port_pair_;
-  bool is_https_;
   BoundNetLog net_log_;
   CompletionCallback callback_;
   scoped_ptr<QuicHttpStream> stream_;