Service Worker: Remove redundant assertions from Cache.put() test case

LayoutTests/http/tests/serviceworker/resources/cache-put-worker.js

 importScripts('worker-testharness.js');
 importScripts('/resources/testharness-helpers.js');
 
 var test_url = 'https://example.com/foo';
 
 // Construct a generic Request object. The URL is |test_url|. All other fields
 // are defaults.
 function new_test_request() {
   return new Request(test_url);
 }
@@ skipping 84 matching lines @@
     var request = new_test_request();
     var response = new Response('', {
         status: 200,
         headers: [['Content-Type', 'text/plain']]
       });
     return cache.put(request, response)
       .then(function() {
           return cache.match(test_url);
         })
       .then(function(result) {
-          assert_object_equals(result, response,
-                               'Cache.put should update the cache with ' +
-                               'new request and response.');
+          assert_equals(result.status, 200, 'Cache.put should store status.');
+          assert_equals(result.headers.get('Content-Type'), 'text/plain',
+                        '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;
@@ skipping 84 matching lines @@
       new TypeError(),
       'Cache.put should throw a TypeError for non-GET requests.');
   }, 'Cache.put with a non-GET request');
 
 cache_test(function(cache) {
     return assert_promise_rejects(
       cache.put(new_test_request(), null),
       new TypeError(),
       'Cache.put should throw a TypeError for an empty response.');
   }, 'Cache.put with an empty response');