Intorduce a separate preference for 'proxy server mode'

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 4799a7f54f40a8c2e6dca46e24b28e7d1973dea3..aa5f308ea488967343eadbf5edf4a31b08be9df3 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1093,11 +1093,12 @@ const char kCloudPrintPrintSystemSettings[] =
 // Used by the service process to determine if the remoting host is enabled.
 const char kRemotingHostEnabled[] = "remoting.host_enabled";
 
-// Boolean to disable proxy altogether. If true, other proxy
-// preferences are ignored.
-const char kNoProxyServer[] = "proxy.disabled";
-// Boolean specifying if proxy should be auto-detected.
-const char kProxyAutoDetect[] = "proxy.auto_detect";
+// Integer to specify the type of proxy settings:
+//  0 = Never use a proxy
+//  1 = Auto detect proxy settings
+//  2 = Manually specify proxy settings
+//  3 = Use system proxy settings
+const char kProxyServerMode[] = "proxy.mode";
 // String specifying the proxy server. For a specification of the expected
 // syntax see net::ProxyConfig::ProxyRules::ParseFromString().
 const char kProxyServer[] = "proxy.server";