Remove redundant serviceworker/cache-* tests

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

-importScripts('worker-testharness.js');
-importScripts('/resources/testharness-helpers.js');
-
-cache_test(function(cache) {
-    return assert_promise_rejects(
-      cache.add(),
-      new TypeError(),
-      'Cache.add should throw a TypeError when no arguments are given.');
-  }, 'Cache.add called with no arguments');
-
-cache_test(function(cache) {
-    return cache.add('simple.txt')
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.add should resolve with undefined on success.');
-        });
-  }, 'Cache.add called with relative URL specified as a string');
-
-cache_test(function(cache) {
-    return assert_promise_rejects(
-      cache.add('javascript://this-is-not-http-mmkay'),
-      'NetworkError',
-      'Cache.add should throw a NetworkError for non-HTTP/HTTPS URLs.');
-  }, 'Cache.add called with non-HTTP/HTTPS URL');
-
-cache_test(function(cache) {
-    var request = new Request('simple.txt', {method: 'POST', body: 'Hello'});
-    return cache.add(request)
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.add should resolve with undefined on success.');
-        });
-  }, 'Cache.add called with Request object');
-
-cache_test(function(cache) {
-    var request = new Request('simple.txt', {method: 'POST', body: 'Hello'});
-    return request.text()
-      .then(function() {
-          assert_true(request.bodyUsed);
-        })
-      .then(function() {
-          return assert_promise_rejects(
-            cache.add(request),
-            new TypeError(),
-            'Cache.add with a Request object with a used body should reject ' +
-            'with a TypeError.');
-        });
-  }, 'Cache.add called with Request object with a used body');
-
-cache_test(function(cache) {
-    var request = new Request('simple.txt', {method: 'POST', body: 'Hello'});
-    return cache.add(request)
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.add should resolve with undefined on success.');
-        })
-      .then(function() {
-          return assert_promise_rejects(
-            cache.add(request),
-            new TypeError(),
-            'Cache.add should throw TypeError if same request is added twice.');
-        });
-  }, 'Cache.add called twice with the same Request object');
-
-cache_test(function(cache) {
-    return cache.add('this-does-not-exist-please-dont-create-it')
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.add should resolve with undefined on success.');
-        });
-  }, 'Cache.add with request that results in a status of 404');
-
-cache_test(function(cache) {
-    return cache.add('fetch-status.php?status=500')
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.add should resolve with undefined on success.');
-        });
-  }, 'Cache.add with request that results in a status of 500');
-
-cache_test(function(cache) {
-    return assert_promise_rejects(
-      cache.addAll(),
-      new TypeError(),
-      'Cache.addAll with no arguments should throw TypeError.');
-  }, 'Cache.addAll with no arguments');
-
-cache_test(function(cache) {
-    // Assumes the existence of simple.txt and blank.html in the same directory
-    // as this test script.
-    var urls = ['simple.txt', undefined, 'blank.html'];
-    return assert_promise_rejects(
-      cache.addAll(),
-      new TypeError(),
-      'Cache.addAll should throw TypeError for an undefined argument.');
-  }, 'Cache.addAll with a mix of valid and undefined arguments');
-
-cache_test(function(cache) {
-    // Assumes the existence of simple.txt and blank.html in the same directory
-    // as this test script.
-    var urls = ['simple.txt', self.location.href, 'blank.html'];
-    return cache.addAll(urls)
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.addAll should resolve with undefined on ' +
-                        'success.');
-        });
-  }, 'Cache.addAll with string URL arguments');
-
-cache_test(function(cache) {
-    // Assumes the existence of simple.txt and blank.html in the same directory
-    // as this test script.
-    var urls = ['simple.txt', self.location.href, 'blank.html'];
-    var requests = urls.map(function(url) {
-        return new Request(url);
-      });
-    return cache.addAll(requests)
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.addAll should resolve with undefined on ' +
-                        'success.');
-        });
-  }, 'Cache.addAll with Request arguments');
-
-cache_test(function(cache) {
-    // Assumes that simple.txt and blank.html exist. The second
-    // resource does not.
-    var urls = ['simple.txt', 'this-resource-should-not-exist', 'blank.html'];
-    var requests = urls.map(function(url) {
-        return new Request(url);
-      });
-    return cache.addAll(requests)
-      .then(function(result) {
-          assert_equals(result, undefined,
-                        'Cache.addAll should resolve with undefined on ' +
-                        'success.');
-        });
-  }, 'Cache.addAll with a mix of succeeding and failing requests');
-
-cache_test(function(cache) {
-    var request = new Request('simple.txt');
-    return assert_promise_rejects(
-      cache.addAll([request, request]),
-      new TypeError(),
-      'Cache.addAll should throw TypeError if the same request is added ' +
-      'twice.');
-  }, 'Cache.addAll called with the same Request object specified twice');