Surface error messages from ONC parsing in about:policy.

chrome/browser/chromeos/cros/onc_network_parser.h

Index: chrome/browser/chromeos/cros/onc_network_parser.h
diff --git a/chrome/browser/chromeos/cros/onc_network_parser.h b/chrome/browser/chromeos/cros/onc_network_parser.h
index 75454f1c569c4693d08344e056d77b9216699041..41a512aaea7f6733a2e11fdf31d49b54de36fb1c 100644
--- a/chrome/browser/chromeos/cros/onc_network_parser.h
+++ b/chrome/browser/chromeos/cros/onc_network_parser.h
@@ -52,6 +52,8 @@ class OncNetworkParser : public NetworkParser {
   virtual Network* CreateNetworkFromInfo(const std::string& service_path,
       const base::DictionaryValue& info) OVERRIDE;
 
+  const std::string& parse_error() { return parse_error_; }
+
  protected:
   OncNetworkParser();
 
@@ -73,6 +75,9 @@ class OncNetworkParser : public NetworkParser {
     int cert_index,
     base::DictionaryValue* certificate);
 
+  // Error message from the JSON parser, if applicable.
+  std::string parse_error_;
+
   scoped_ptr<base::DictionaryValue> root_dict_;
   base::ListValue* network_configs_;
   base::ListValue* certificates_;