[ios] Pass more --jscomp_error switches to the closure Compiler.

components/translate/ios/browser/resources/translate_ios.js

 // Copyright 2014 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.
 
-__gCrWeb['translate'] = {};
+/**
+ * @fileoverview Installs Translate management functions on the __gCrWeb object.
+ *
+ * TODO(crbug.com/659442): Enable checkTypes, checkVars errors for this file.
+ * @suppress {checkTypes, checkVars}
+ */
+
+__gCrWeb.translate = {};
+__gCrWeb['translate'] = __gCrWeb.translate;
 
 (function() {
 /**
  * The delay a wait performed (in milliseconds) before checking whether the
  * translation has finished.
  * @type {number}
  */
 __gCrWeb.translate.TRANSLATE_STATUS_CHECK_DELAY = 400;
 
 /**
@@ skipping 54 matching lines @@
         'originalPageLanguage': cr.googleTranslate.sourceLang,
         'translationTime': cr.googleTranslate.translationTime});
   } else {
     // The translation is still pending, check again later.
     window.setTimeout(__gCrWeb.translate.checkTranslateStatus,
                       __gCrWeb.translate.TRANSLATE_STATUS_CHECK_DELAY);
   }
 }
 
 }());  // anonymous function