Add LayoutTests for the behavior of navigation redirect with Service Worker.

LayoutTests/http/tests/serviceworker/resources/navigation-redirect-worker.js

Index: LayoutTests/http/tests/serviceworker/resources/navigation-redirect-worker.js
diff --git a/LayoutTests/http/tests/serviceworker/resources/navigation-redirect-worker.js b/LayoutTests/http/tests/serviceworker/resources/navigation-redirect-worker.js
new file mode 100644
index 0000000000000000000000000000000000000000..69ddbed451abc9d3fd5fc4599d522cfe1c65898c
--- /dev/null
+++ b/LayoutTests/http/tests/serviceworker/resources/navigation-redirect-worker.js
@@ -0,0 +1,47 @@
+// TODO(horo): Service worker can be killed at some point during the test. So we
+// should use storage API instead of this global variable.
+var urls = [];
+
+self.addEventListener('message', function(event) {
+    event.data.port.postMessage({urls: urls});
+    urls = [];
+  });
+
+function get_query_params(url) {
+  var search = (new URL(url)).search;
+  if (!search) {
+    return {};
+  }
+  var ret = {};
+  var params = search.substring(1).split('&');
+  params.forEach(function(param) {
+      var element = param.split('=');
+      ret[decodeURIComponent(element[0])] = decodeURIComponent(element[1]);
+    });
+  return ret;
+}
+
+self.addEventListener('fetch', function(event) {
+    urls.push(event.request.url)
+    var params = get_query_params(event.request.url);
+    if (params['sw'] == 'gen') {
+      event.respondWith(Response.redirect(params['url']));
+    } else if (params['sw'] == 'fetch') {
+      event.respondWith(fetch(event.request));
+    } else if (params['sw'] == 'opaque') {
+      event.respondWith(fetch(
+          new Request(event.request.url, {redirect: 'manual'})));
+    } else if (params['sw'] == 'opaqueThroughCache') {
+      var url = event.request.url;
+      var cache;
+      event.respondWith(
+          self.caches.delete(url)
+            .then(function() { return self.caches.open(url); })
+            .then(function(c) {
+                cache = c;
+                return fetch(new Request(url, {redirect: 'manual'}));
+              })
+            .then(function(res) { return cache.put(event.request, res); })
+            .then(function() { return cache.match(url); }));
+    }
+  });