Add an additional per-request DNS cache when executing FindProxyForURL() from...

net/proxy/proxy_resolver_request_context.h

+// 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.
+
+#ifndef NET_PROXY_PROXY_RESOLVER_REQUEST_CONTEXT_H_
+#define NET_PROXY_PROXY_RESOLVER_REQUEST_CONTEXT_H_
+
+namespace net {
+
+class HostCache;
+class BoundNetLog;
+
+// This data structure holds state related to an invocation of
+// "FindProxyForURL()". It is used to associate per-request
+// data that can be retrieved by the bindings.
+struct ProxyResolverRequestContext {
+  // All of these pointers are expected to remain valid for duration of
+  // this instance's lifetime.
+  ProxyResolverRequestContext(const GURL* query_url,
+                              const BoundNetLog* net_log,
+                              HostCache* host_cache)
+    : query_url(query_url),
+      net_log(net_log),
+      host_cache(host_cache) {
+  }
+
+  const GURL* query_url;

[wtc, 2010/06/23 00:59:02]

You forgot to remove the query_url, which I believe is unused.

+  const BoundNetLog* net_log;
+  HostCache* host_cache;
+};
+
+}  // namespace net
+
+#endif  // NET_PROXY_PROXY_RESOLVER_REQUEST_CONTEXT_H_