Add a feature to the HostResolverRules to be able to match rules only...

net/base/host_mapping_rules.cc

Index: net/base/host_mapping_rules.cc
===================================================================
--- net/base/host_mapping_rules.cc	(revision 56811)
+++ net/base/host_mapping_rules.cc	(working copy)
@@ -28,8 +28,18 @@
        it != map_rules_.end(); ++it) {
     const MapRule& rule = *it;
 
-    if (!MatchPatternASCII(host_port->host(), rule.hostname_pattern))
-      continue;  // This rule doesn't apply.
+    // The rule's hostname_pattern will be something like:
+    //     www.foo.com
+    //     *.foo.com
+    //     www.foo.com:1234
+    //     *.foo.com:1234
+    // First, we'll check for a match just on hostname.
+    // If that fails, we'll check for a match with both hostname and port.
+    if (!MatchPatternASCII(host_port->host(), rule.hostname_pattern)) {
+      std::string host_port_string = host_port->ToString();
+      if (!MatchPatternASCII(host_port_string, rule.hostname_pattern))
+        continue;  // This rule doesn't apply.
+    }
 
     host_port->set_host(rule.replacement_hostname);
     if (rule.replacement_port != -1)