Correct the skip-waiting-installed.html behavior

According to the latest spec, the skipWaiting promise should be resolved
after 'activate' event is dispatched. This change is from
w3c/ServiceWorker#1065.

Tracing through the spec, skipWaiting() enters "Try Activate".
"Try Activate" invokes "Activate". "Activate" blocks until the final step:
"13. Run the Update Worker State algorithm passing registration’s active
worker and activated as the arguments."

"Update Worker State" queues a task to set ServiceWorker#state to 'activated'.
But in step 10, we have dispatched the 'activate' event. Therefore the order
should be:
1. 'activate' event handler runs
2. skipWaiting() promise resolves
3. ServiceWorker#state is set to 'activated'

So we correct the test case here and delete all the wrong expected files.

BUG=725616

Change-Id: Id0765988c7cdf48f39bb73ccb3fc0cce6ea60949
Reviewed-on: https://chromium-review.googlesource.com/646244
Commit-Queue: Matt Falkenhagen <[email protected]>
Reviewed-by: Matt Falkenhagen <[email protected]>
Cr-Commit-Position: refs/heads/master@{#499513}

third_party/WebKit/LayoutTests/external/wpt/service-workers/service-worker/resources/skip-waiting-installed-worker.js

@@ -1,29 +1,27 @@
-self.state = 'starting';
-
-self.addEventListener('install', function() {
-    self.state = 'installing';
-  });
+var saw_activate_event = false
 
 self.addEventListener('activate', function() {
-    self.state = 'activating';
+    saw_activate_event = true;
   });
 
 self.addEventListener('message', function(event) {
     var port = event.data.port;
-    if (self.state !== 'installing') {
-      port.postMessage('FAIL: Worker should be waiting in installed state');
-      return;
-    }
     event.waitUntil(self.skipWaiting()
       .then(function(result) {
           if (result !== undefined) {
             port.postMessage('FAIL: Promise should be resolved with undefined');
             return;
           }
 
-          if (self.state === 'activating') {
+          if (!saw_activate_event) {
+            port.postMessage(
+                'FAIL: Promise should be resolved after activate event is dispatched');
+            return;
+          }
+
+          if (self.registration.active.state !== 'activating') {
             port.postMessage(
-                'FAIL: Promise should be resolved before worker is activated');
+                'FAITL: Promise should be resolved before ServiceWorker#state is set to activated');
             return;
           }