Cache Storage API tests: Fix WPT test bugs, remove redundant local copies

third_party/WebKit/LayoutTests/external/wpt/service-workers/cache-storage/resources/test-helpers.js

 (function() {
   var next_cache_index = 1;
 
   // Returns a promise that resolves to a newly created Cache object. The
   // returned Cache will be destroyed when |test| completes.
   function create_temporary_cache(test) {
     var uniquifier = String(++next_cache_index);
     var cache_name = self.location.pathname + '/' + uniquifier;
 
     test.add_cleanup(function() {
@@ skipping 218 matching lines @@
     assert_true(expected_array.some(function(element) {
         try {
             assert_response_equals(actual, element);
             return true;
         } catch (e) {
             return false;
         }
     }), description);
 }
 
+// Helper for testing with Request objects. Compares simple
+// attributes defined on the interfaces, as well as the headers.
+function assert_request_equals(actual, expected, description) {
+    assert_class_string(actual, "Request", description);
+    ["url"].forEach(function(attribute) {
+        assert_equals(actual[attribute], expected[attribute],
+                      description + " Attributes differ: " + attribute + ".");
+    });
+    assert_header_equals(actual.headers, expected.headers, description);
+}
+
+// Asserts that two arrays |actual| and |expected| contain the same
+// set of Requests as determined by assert_request_equals(). The
+// corresponding elements must occupy corresponding indices in their
+// respective arrays.
+function assert_request_array_equals(actual, expected, description) {
+    assert_true(Array.isArray(actual), description);
+    assert_equals(actual.length, expected.length, description);
+    actual.forEach(function(value, index) {
+        assert_request_equals(value, expected[index],
+                              description + " : object[" + index + "]");
+    });
+}
+
 // Deletes all caches, returning a promise indicating success.
 function delete_all_caches() {
   return self.caches.keys()
     .then(function(keys) {
       return Promise.all(keys.map(self.caches.delete.bind(self.caches)));
     });
 }