ServiceWorker: Add support for .skipWaiting and controllerchange event(3/3)

LayoutTests/http/tests/serviceworker/resources/skip-waiting-installed-worker.js

Index: LayoutTests/http/tests/serviceworker/resources/skip-waiting-installed-worker.js
diff --git a/LayoutTests/http/tests/serviceworker/resources/skip-waiting-installed-worker.js b/LayoutTests/http/tests/serviceworker/resources/skip-waiting-installed-worker.js
new file mode 100644
index 0000000000000000000000000000000000000000..12fdb47ba725c59f6aca71e1501c480a00e38ddd
--- /dev/null
+++ b/LayoutTests/http/tests/serviceworker/resources/skip-waiting-installed-worker.js
@@ -0,0 +1,33 @@
+self.state = 'starting';
+
+self.addEventListener('install', function() {
+    self.state = 'installing';
+  });
+
+self.addEventListener('activate', function() {
+    self.state = 'activating';
+  });
+
+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;
+    }
+    self.skipWaiting()
+      .then(function(result) {
+          if (result !== undefined) {
+            port.postMessage('FAIL: Promise should be resolved with undefined');
+            return;
+          }
+          if (self.state !== 'activating') {
+            port.postMessage(
+                'FAIL: Promise should be resolved after worker activated');
+            return;
+          }
+          port.postMessage('PASS');
+        })
+      .catch(function(e) {
+          port.postMessage('FAIL: unexpected exception: ' + e);
+        });
+  });