Extract the parsing of proxy rules to ProxyConfig::ProxyRules, and unit-test....

net/proxy/proxy_info.cc

Index: net/proxy/proxy_info.cc
===================================================================
--- net/proxy/proxy_info.cc	(revision 12729)
+++ net/proxy/proxy_info.cc	(working copy)
@@ -23,6 +23,10 @@
   proxy_list_.Set(proxy_uri_list);
 }
 
+void ProxyInfo::UseProxyServer(const ProxyServer& proxy_server) {
+  proxy_list_.SetSingleProxyServer(proxy_server);
+}
+
 std::string ProxyInfo::ToPacString() {
   return proxy_list_.ToPacString();
 }