Use asserts in origin trials layout tests

third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/resources/foreignfetch-origin-trial-interfaces-worker-enabled.php

Index: third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/resources/foreignfetch-origin-trial-interfaces-worker-enabled.php
diff --git a/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/resources/foreignfetch-origin-trial-interfaces-worker-enabled.php b/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/resources/foreignfetch-origin-trial-interfaces-worker-enabled.php
new file mode 100644
index 0000000000000000000000000000000000000000..8b1a3fedd0919997048122f15efb3a3b4725a607
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/http/tests/origin_trials/webexposed/resources/foreignfetch-origin-trial-interfaces-worker-enabled.php
@@ -0,0 +1,19 @@
+<?php
+// Generate token with the command:
+// generate_token.py  http://127.0.0.1:8000 ForeignFetch -expire-timestamp=2000000000
+header("Origin-Trial: AinuK1QNcHGJANXfN0Pzkvpxm8rocd4kcqQqhp7rBN8PEX/1JicCoDXX3fIhk7iwBOCCOQYR0cvZ8XHTLJJfVw0AAABUeyJvcmlnaW4iOiAiaHR0cDovLzEyNy4wLjAuMTo4MDAwIiwgImZlYXR1cmUiOiAiRm9yZWlnbkZldGNoIiwgImV4cGlyeSI6IDIwMDAwMDAwMDB9");
+header('Content-Type: application/javascript');
+?>
+importScripts('../../../resources/testharness.js');
+importScripts('../../../resources/origin-trials-helper.js');
+
+test(t => {
+  OriginTrialsHelper.check_properties(this,
+    {'InstallEvent':['registerForeignFetch'],
+     'global':['onforeignfetch']});
+}, 'ForeignFetch related properties on interfaces in service worker, with trial enabled.');
+
+test(t => {
+  OriginTrialsHelper.check_interfaces(this,
+    ['ForeignFetchEvent']);
+}, 'ForeignFetch related interfaces in service worker, with trial enabled.');