Deprecate instead of close SPDY sessions upon network change.

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 338 matching lines @@
   // the session as permanently closed. Callers must assume that the
   // session is destroyed after this is called. (However, it may not
   // be destroyed right away, e.g. when a SpdySession function is
   // present in the call stack.)
   //
   // |err| should be < ERR_IO_PENDING; this function is intended to be
   // called on error.
   // |description| indicates the reason for the error.
   void CloseSessionOnError(Error err, const std::string& description);
 
+  // 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.
   bool IsReused() const;
 
   // Returns true if the underlying transport socket ever had any reads or
   // writes.
@@ skipping 745 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_