Use sockets with unread data if they've never been used before.

net/spdy/spdy_session.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_SPDY_SPDY_SESSION_H_
 #define NET_SPDY_SPDY_SESSION_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 349 matching lines @@
   // Mark this session as unavailable, meaning that it will not be used to
   // service new streams. Unlike when a GOAWAY frame is received, this function
   // will not close any streams.
   void MakeUnavailable();
 
   // Retrieves information on the current state of the SPDY session as a
   // Value.  Caller takes possession of the returned value.
   base::Value* GetInfoAsValue() const;
 
   // Indicates whether the session is being reused after having successfully
-  // used to send/receive data in the past.
+  // used to send/receive data in the past or if the underlying socket was idle
+  // before being used for a SPDY session.
   bool IsReused() const;
 
   // Returns true if the underlying transport socket ever had any reads or
   // writes.
   bool WasEverUsed() const {
     return connection_->socket()->WasEverUsed();
   }
 
   // Returns the load timing information from the perspective of the given
   // stream.  If it's not the first stream, the connection is considered reused
@@ skipping 739 matching lines @@
   // This SPDY proxy is allowed to push resources from origins that are
   // different from those of their associated streams.
   HostPortPair trusted_spdy_proxy_;
 
   TimeFunc time_func_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_SESSION_H_