Keep webdriverjs es5 strict mode compatible.

A follow up to commit c8b388a

Author: sevaseva

javascript/webdriver/build.desc

@@ -97,6 +97,7 @@ js_binary(name = "webdriver",
  "--jscomp_error=undefinedVars",
  "--jscomp_error=unknownDefines",
  "--jscomp_error=uselessCode",
+ "--jscomp_error=useOfGoogBase",
  "--jscomp_error=visibility",
  "--output_wrapper='(function(exports){%output%})(typeof exports===typeof {}&&exports===this?exports:this.webdriver=this.webdriver||{})'",
  "--third_party=false",