Expose Cache Storage API in global window/worker scope

LayoutTests/http/tests/cachestorage/script-tests/cache-put.js

-importScripts('worker-testharness.js');
-importScripts('/resources/testharness-helpers.js');
-importScripts('override_assert_object_equals.js');
+if (self.importScripts) {
+    importScripts('/resources/testharness.js');
+    importScripts('/resources/testharness-helpers.js');
+    importScripts('../resources/test-helpers.js');
+}
 
 var test_url = 'https://example.com/foo';
 var test_body = 'Hello world!';
 
 cache_test(function(cache) {
     var request = new Request(test_url);
     var response = new Response(test_body);
     return cache.put(request, response)
       .then(function(result) {
           assert_equals(result, undefined,
                         'Cache.put should resolve with undefined on success.');
         });
   }, 'Cache.put called with simple Request and Response');
 
 cache_test(function(cache) {
-    var test_url = new URL('simple.txt', location.href).href;
+    var test_url = new URL('../resources/simple.txt', location.href).href;
     var request = new Request(test_url);
     var response;
     return fetch(test_url)
       .then(function(fetch_result) {
           response = fetch_result.clone();
           return cache.put(request, fetch_result);
         })
       .then(function() {
           return cache.match(test_url);
         })
@@ skipping 88 matching lines @@
                         'Cache.put should store headers.');
           return result.text();
         })
       .then(function(body) {
           assert_equals(body, '',
                         'Cache.put should store response body.');
         });
   }, 'Cache.put with an empty response body');
 
 cache_test(function(cache) {
-    var test_url = new URL('fetch-status.php?status=500', location.href).href;
+    var test_url = new URL('../resources/fetch-status.php?status=500', location.href).href;
     var request = new Request(test_url);
     var response;
     return fetch(test_url)
       .then(function(fetch_result) {
           assert_equals(fetch_result.status, 500,
                         'Test framework error: The status code should be 500.');
           response = fetch_result.clone();
           return cache.put(request, fetch_result);
         })
       .then(function() {
@@ skipping 175 matching lines @@
       assert_true(
         response.bodyUsed,
         '[https://fetch.spec.whatwg.org/#concept-body-consume-body] ' +
           'The text() method should consume the body of the response.');
       return assert_promise_rejects(
         cache.put(new Request(test_url), response),
         new TypeError(),
         'Cache.put should throw a TypeError for a response with used body.');
     });
   }, 'Cache.put with a used response body');
+
+done();