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

chrome/browser/automation/automation_provider.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/automation/automation_provider.h"
 
 #include <set>
 
 #include "base/callback.h"
 #include "base/debug/trace_event.h"
@@ skipping 532 matching lines @@
       return;
     }
     bool auto_config;
     if (dict.GetBoolean(automation::kJSONProxyAutoconfig, &auto_config)) {
       pc->set_auto_detect(true);
     }
     std::string pac_url;
     if (dict.GetString(automation::kJSONProxyPacUrl, &pac_url)) {
       pc->set_pac_url(GURL(pac_url));
     }
+    bool pac_mandatory;
+    if (dict.GetBoolean(automation::kJSONProxyPacMandatory, &pac_mandatory)) {
+      pc->set_pac_mandatory(pac_mandatory);
+    }
     std::string proxy_bypass_list;
     if (dict.GetString(automation::kJSONProxyBypassList, &proxy_bypass_list)) {
       pc->proxy_rules().bypass_rules.ParseFromString(proxy_bypass_list);
     }
     std::string proxy_server;
     if (dict.GetString(automation::kJSONProxyServer, &proxy_server)) {
       pc->proxy_rules().ParseFromString(proxy_server);
     }
   }
 
@@ skipping 396 matching lines @@
 
 void AutomationProvider::SaveAsAsync(int tab_handle) {
   NavigationController* tab = NULL;
   TabContents* tab_contents = GetTabContentsForHandle(tab_handle, &tab);
   if (tab_contents) {
     TabContentsWrapper* wrapper =
         TabContentsWrapper::GetCurrentWrapperForContents(tab_contents);
     wrapper->download_tab_helper()->OnSavePage();
   }
 }