pass script fetch start / end time to Transalte Element to implement real time latency monitoring

components/translate/core/browser/resources/translate.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.
 
 // This code is used in conjunction with the Google Translate Element script.
 // It is executed in an isolated world of a page to translate it from one
 // language to another.
 // It should be included in the page before the Translate Element script.
 
 var cr = cr || {};
@@ skipping 241 matching lines @@
      * Entry point called by the Translate Element once it has been injected in
      * the page.
      */
     onTranslateElementLoad: function() {
       loadedTime = performance.now();
       try {
         lib = google.translate.TranslateService({
           // translateApiKey is predefined by translate_script.cc.
           'key': translateApiKey,
           'serverParams': serverParams,
+          'timeInfo': gtTimeInfo,

[groby-ooo-7-16, 2016/08/18 22:35:04]

key is 'timeInfo' here, 'gtTimeInfo' in test - maybe a typo?

[ftang, 2016/08/18 23:01:39]

the JavaScript variable in the test is gtTimeInfo. The value appended by the
translate_script.cc is also gtTimeInfo. This JS code pass that gtTimeInfo into
the  google.translate.TranslateService() inside an object keyed 'timeInfo'. The
'timeInfo' will be later read by js code in TranslateElement (see
https://critique.corp.google.com/#review/130658595/depot/google3/googledata/t...
) 

[groby-ooo-7-16, 2016/08/19 18:20:59]

Ah, I see - thank you for the explanation.

[ftang, 2016/08/19 20:33:23]

Acknowledged.

           'useSecureConnection': true
         });
         translateApiKey = undefined;
         serverParams = undefined;
+        gtTimeInfo = undefined;
       } catch (err) {
         errorCode = ERROR['INITIALIZATION_ERROR'];
         translateApiKey = undefined;
         serverParams = undefined;
+        gtTimeInfo = undefined;
         return;
       }
       // The TranslateService is not available immediately as it needs to start
       // Flash.  Let's wait until it is ready.
       checkLibReady();
     },
 
     /**
      * Entry point called by the Translate Element when it want to load an
      * external CSS resource into the page.
@@ skipping 28 matching lines @@
         if (this.status != 200) {
           errorCode = ERROR['SCRIPT_LOAD_ERROR'];
           return;
         }
         eval(this.responseText);
       }
       xhr.send();
     }
   };
 })();