Change ProxyRules to handle ProxyLists rather than just single ProxyServer instances.

net/proxy/proxy_info.cc

Index: net/proxy/proxy_info.cc
diff --git a/net/proxy/proxy_info.cc b/net/proxy/proxy_info.cc
index dd68820c1dec06876f793a44bf554d2300cbf659..0f996a2b3f95095472e6f4356bd3817841f74de2 100644
--- a/net/proxy/proxy_info.cc
+++ b/net/proxy/proxy_info.cc
@@ -49,6 +49,11 @@ void ProxyInfo::UseProxyServer(const ProxyServer& proxy_server) {
   proxy_list_.SetSingleProxyServer(proxy_server);
 }
 
+void ProxyInfo::UsePacString(const std::string& pac_string) {
+  Reset();
+  proxy_list_.SetFromPacString(pac_string);
+}
+
 std::string ProxyInfo::ToPacString() const {
   return proxy_list_.ToPacString();
 }