Add named testing interface

chrome/common/automation_constants.cc

Index: chrome/common/automation_constants.cc
===================================================================
--- chrome/common/automation_constants.cc	(revision 67218)
+++ chrome/common/automation_constants.cc	(working copy)
@@ -5,6 +5,7 @@
 #include "chrome/common/automation_constants.h"
 
 namespace automation {
+
 // JSON value labels for proxy settings that are passed in via
 // AutomationMsg_SetProxyConfig.
 const char kJSONProxyAutoconfig[] = "proxy.autoconfig";
@@ -12,4 +13,10 @@
 const char kJSONProxyPacUrl[] = "proxy.pac_url";
 const char kJSONProxyBypassList[] = "proxy.bypass_list";
 const char kJSONProxyServer[] = "proxy.server";
-}
+
+// Named testing interface is used when you want to connect an
+// AutomationProxy to an already-running browser instance.
+const char kNamedInterfacePrefix[] = "NamedTestingInterface:";
+
+}  // namespace automation
+