[ServiceWorker] Fix bugs of wpt tests for Client.navigate

third_party/WebKit/LayoutTests/external/wpt/resources/testharness.js

Index: third_party/WebKit/LayoutTests/external/wpt/resources/testharness.js
diff --git a/third_party/WebKit/LayoutTests/external/wpt/resources/testharness.js b/third_party/WebKit/LayoutTests/external/wpt/resources/testharness.js
index 73913d6d32c3178be1a33d9c3a534afd8bbdffce..165a17f346d7fecb960458e722e382253fd4beef 100644
--- a/third_party/WebKit/LayoutTests/external/wpt/resources/testharness.js
+++ b/third_party/WebKit/LayoutTests/external/wpt/resources/testharness.js
@@ -483,7 +483,10 @@ policies and contribution forms [3].
     }
 
     function is_service_worker(worker) {
-        return 'ServiceWorker' in self && worker instanceof ServiceWorker;
+        // The worker object may be from other execution context,

[falken, 2017/05/29 01:07:04]

s/other/another

[leonhsl(Using Gerrit), 2017/05/29 13:09:54]

Acknowledged.

[leonhsl(Using Gerrit), 2017/06/10 02:57:44]

Done.

+        // so do not use instanceof here.
+        return 'ServiceWorker' in self &&
+            Object.prototype.toString.call(worker) == '[object ServiceWorker]';

[leonhsl(Using Gerrit), 2017/05/28 09:12:59]

Another optional solution without changing testharness.js here:
Change client-navigate.https.html to pass reg.installing instead of
frame.contentWindow.navigator.serviceWorker.controller as sw object when calling
fetch_tests_from_worker(sw). 

I'd prefer to change is_service_worker() here.

[Mike West, 2017/05/29 08:02:44]

I'm not sure we can do that via this update mechanism, both because it's in a
separate repository, and because I'm not sure whether folks are on board with
individual vendors changing central infrastructure without cross-org review.
+foolip@ who will know whether we can upstream changes to `testharness.js` this
way.

     }
 
     /*