Enable (optional) blocking of webrequests in case a PAC script cannot be fetched or is invalid.

chrome/browser/prefs/command_line_pref_store.cc

Index: chrome/browser/prefs/command_line_pref_store.cc
diff --git a/chrome/browser/prefs/command_line_pref_store.cc b/chrome/browser/prefs/command_line_pref_store.cc
index 2f4c3166b9dd93917a18bc152640bd43509d5c4a..c5d0999d2aafd443eda8668eb926d7efe6c1a998 100644
--- a/chrome/browser/prefs/command_line_pref_store.cc
+++ b/chrome/browser/prefs/command_line_pref_store.cc
@@ -84,7 +84,7 @@ void CommandLinePrefStore::ApplyProxyMode() {
     std::string pac_script_url =
         command_line_->GetSwitchValueASCII(switches::kProxyPacUrl);
     SetValue(prefs::kProxy,
-             ProxyConfigDictionary::CreatePacScript(pac_script_url));
+             ProxyConfigDictionary::CreatePacScript(pac_script_url, false));
   } else if (command_line_->HasSwitch(switches::kProxyAutoDetect)) {
     SetValue(prefs::kProxy,
              ProxyConfigDictionary::CreateAutoDetect());