Deprecate instead of close SPDY sessions upon network change.

net/spdy/spdy_session.h

Index: net/spdy/spdy_session.h
diff --git a/net/spdy/spdy_session.h b/net/spdy/spdy_session.h
index fde42024be8f54291338e01b246d797af7212f7c..70f0d4bf8d0004323a255423038926a6d3e8d67c 100644
--- a/net/spdy/spdy_session.h
+++ b/net/spdy/spdy_session.h
@@ -353,6 +353,11 @@ class NET_EXPORT SpdySession : public BufferedSpdyFramerVisitorInterface,
   // |description| indicates the reason for the error.
   void CloseSessionOnError(Error err, const std::string& description);
 
+  // Mark this session as going away. It should not be used for new streams but
+  // currently active streams are left alone. Pending requests for new streams
+  // and created-but-inactive streams fail with |err|.
+  void Deprecate(Error err);
+
   // Retrieves information on the current state of the SPDY session as a
   // Value.  Caller takes possession of the returned value.
   base::Value* GetInfoAsValue() const;
@@ -887,6 +892,9 @@ class NET_EXPORT SpdySession : public BufferedSpdyFramerVisitorInterface,
   // empty.
   SpdyStreamId PopStreamToPossiblyResume();
 
+  // Perform the work resulting from reception of a GOAWAY message.
+  void GoAway(SpdyStreamId last_accepted_stream_id, Error err);
+
   // --------------------------
   // Helper methods for testing
   // --------------------------