Include the document URL in the load_time_data.js expectation failures.

ui/webui/resources/js/load_time_data.js

 // Copyright (c) 2012 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.
 
 /**
  * @fileoverview This file defines a singleton which provides access to all data
  * that is available as soon as the page's resources are loaded (before DOM
  * content has finished loading). This data includes both localized strings and
  * any data that is important to have ready from a very early stage (e.g. things
  * that must be displayed right away).
@@ skipping 100 matching lines @@
       }
     }
   };
 
   /**
    * Checks condition, displays error message if expectation fails.
    * @param {*} condition The condition to check for truthiness.
    * @param {string} message The message to display if the check fails.
    */
   function expect(condition, message) {
-    if (!condition)
-      console.error(message);
+    if (!condition) {
+      console.error('Unexpected condition on ' + document.location.href + ': ' +
+                    message);
+    }
   }
 
   /**
    * Checks that the given value has the given type.
    * @param {string} id The id of the value (only used for error message).
    * @param {*} value The value to check the type on.
    * @param {string} type The type we expect |value| to be.
    */
   function expectIsType(id, value, type) {
     expect(typeof value == type, '[' + value + '] (' + id +
                                  ') is not a ' + type);
   }
 
   expect(!loadTimeData, 'should only include this file once');
   loadTimeData = new LoadTimeData;
 })();