Fix wait error messages.

Author: jleyba

javascript/webdriver/until.js

@@ -64,7 +64,7 @@ var until = webdriver.until;
  */
 until.Condition = function(message, fn) {
   /** @private {string} */
-  this.description_ = message;
+  this.description_ = 'Waiting ' + message;
 
   /** @type {function(!webdriver.WebDriver): OUT} */
   this.fn = fn;

javascript/webdriver/webdriver.js

@@ -648,7 +648,7 @@ webdriver.WebDriver.prototype.wait = function(
       return webdriver.promise.consume(fn, null, [driver]);
     }
     return fn(driver);
-  }, timeout, opt_message);
+  }, timeout, message);
 };