Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/proxy/proxy_server.cc

 // Copyright (c) 2010 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.
 
 #include "net/proxy/proxy_server.h"
 
 #include <algorithm>
 
 #include "base/strings/string_util.h"
 #include "net/base/url_util.h"
@@ skipping 191 matching lines @@
       break;
   }
   return -1;
 }
 
 // static
 ProxyServer::Scheme ProxyServer::GetSchemeFromURI(const std::string& scheme) {
   return GetSchemeFromURIInternal(scheme);
 }
 
+size_t ProxyServer::EstimateMemoryUsage() const {
+  return HostPortPair::EstimateMemoryUsage(host_port_pair_);

[Bence, 2017/02/02 14:15:19]

1.It's just a string, how bad can it get?  Few dozen bytes?
2. Why do we not account for memory used by enum Scheme (maybe 64 bits depending
on memory alignment requirements)?
3. Why does HostPortPair::EstimateMemoryUsage() not account for uint16 port,
only the string?

I do not mean to be nitpicking, but since there are multiple kilobyte buffers
and containers hanging around, it feels arbitrary to me to account for few dozen
byte long strings, but not go all the way and account for ints.

[xunjieli, 2017/02/02 14:53:42]

dskiba@ can correct me if I am wrong. My understanding is that EMU() should only
account for dynamically allocated memory. For members(such as enum and ints)
that do not allocate, we don't track them. The static allocated memory is
accounted for in a tree Node.
More discussion on this topic can be found in a review comment here:
https://codereview.chromium.org/2650943007/diff/100001/net/base/host_port_pai...

[Bence, 2017/02/02 15:05:08]

Ah okay, that makes perfect sense.  Thank you for the explanation.

+}
+
 // static
 ProxyServer ProxyServer::FromSchemeHostAndPort(
     Scheme scheme,
     std::string::const_iterator begin,
     std::string::const_iterator end) {
 
   // Trim leading/trailing space.
   HttpUtil::TrimLWS(&begin, &end);
 
   if (scheme == SCHEME_DIRECT && begin != end)
@@ skipping 13 matching lines @@
     if (port == -1)
       port = GetDefaultPortForScheme(scheme);
 
     host_port_pair = HostPortPair(host, static_cast<uint16_t>(port));
   }
 
   return ProxyServer(scheme, host_port_pair);
 }
 
 }  // namespace net