Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/spdy_session_key.h

 // Copyright (c) 2013 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_KEY_H_
 #define NET_SPDY_SPDY_SESSION_KEY_H_
 
 #include "net/base/net_export.h"
 #include "net/base/privacy_mode.h"
 #include "net/proxy/proxy_server.h"
@@ skipping 31 matching lines @@
   }
 
   const ProxyServer& proxy_server() const {
     return host_port_proxy_pair_.second;
   }
 
   PrivacyMode privacy_mode() const {
     return privacy_mode_;
   }
 
+  // Returns the estimate of dynamically allocated memory in bytes.
+  size_t EstimateMemoryUsage() const;
+
  private:
   HostPortProxyPair host_port_proxy_pair_;
   // If enabled, then session cannot be tracked by the server.
   PrivacyMode privacy_mode_;
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_SESSION_KEY_H_