[WPT] Add Fetch API, redirect tests for webbundle subresource loading

Change-Id: I4044fbf55b82e998433c118fe0b6130ae3842966
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2409253
Reviewed-by: Tsuyoshi Horo <horo@chromium.org>
Reviewed-by: Kunihiko Sakamoto <ksakamoto@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806889}

web-bundle/subresource-loading/subresource-loading-from-web-bundle.tentative.html

@@ -15,6 +15,18 @@
       assert_equals(module.result, 'OK');
     }, "Subresource loading with WebBundle");
 
+    promise_test(async () => {
+      const response = await fetch('http://web-platform.test:8001/root.js');
+      const text = await response.text();
+      assert_equals(text, "export * from './submodule.js';\n");
+    }, "Subresource loading with WebBundle (Fetch API)");
+
+    promise_test(t => {
+      const url =
+          '/common/redirect.py?location=http://web-platform.test:8001/root.js';
+      return promise_rejects_js(t, TypeError, import(url));
+    }, "Subresource loading with WebBundle shouldn't affect redirect");
+
     promise_test(async () => {
       const link = document.createElement("link");
       link.rel = "webbundle";