Allow SpdySessionPool to find/create SpdySession with IP pooling disabled.

net/spdy/spdy_session.cc

Index: net/spdy/spdy_session.cc
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 2b47a81262ca65cedea88509aa3ae99ddafb02f9..e217fc2a067238a70631aadda0599684387bc715 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -1332,6 +1332,10 @@ void SpdySession::AddPooledAlias(const SpdySessionKey& alias_key) {
   pooled_aliases_.insert(alias_key);
 }
 
+void SpdySession::RemovePooledAlias(const SpdySessionKey& alias_key) {
+  pooled_aliases_.erase(alias_key);
+}
+
 bool SpdySession::HasAcceptableTransportSecurity() const {
   // If we're not even using TLS, we have no standards to meet.
   if (!is_secure_) {