[CacheStorage] Keep deleted caches alive until last reference is gone

third_party/WebKit/LayoutTests/http/tests/cachestorage/script-tests/cache-storage.js

 if (self.importScripts) {
     importScripts('/resources/testharness.js');
     importScripts('../resources/test-helpers.js');
 }
 
 promise_test(function(t) {
     var cache_name = 'cache-storage/foo';
     return self.caches.delete(cache_name)
       .then(function() {
           return self.caches.open(cache_name);
         })
       .then(function(cache) {
           assert_true(cache instanceof Cache,
                       'CacheStorage.open should return a Cache.');
         });
   }, 'CacheStorage.open');
 
 promise_test(function(t) {
+    var cache_name = 'cache-storage/bar';
+    var first_cache = null;
+    var second_cache = null;
+    return self.caches.open(cache_name)
+      .then(function(cache) {
+          first_cache = cache;
+          return self.caches.delete(cache_name);
+        })
+      .then(function() {
+          return first_cache.add('../resources/simple.txt');
+        })
+      .then(function() {
+          return self.caches.keys();
+        })
+      .then(function(cache_names) {
+          assert_equals(cache_names.indexOf(cache_name), -1);
+          return self.caches.open(cache_name);
+        })
+      .then(function(cache) {
+          second_cache = cache;
+          return second_cache.keys();
+        })
+      .then(function(keys) {
+          assert_equals(keys.length, 0);
+          return first_cache.keys();
+        })
+      .then(function(keys) {
+          assert_equals(keys.length, 1);
+          // Clean up
+          return self.caches.delete(cache_name);
+        })
+  }, 'CacheStorage.delete dooms');
+
+promise_test(function(t) {
     // Note that this test may collide with other tests running in the same
     // origin that also uses an empty cache name.
     var cache_name = '';
     return self.caches.delete(cache_name)
       .then(function() {
           return self.caches.open(cache_name);
         })
       .then(function(cache) {
           assert_true(cache instanceof Cache,
                       'CacheStorage.open should accept an empty name.');
@@ skipping 159 matching lines @@
                       'CacheStorage names should be not be converted.');
         })
       .then(function() { return self.caches.has(converted_name); })
       .then(function(cache_exists) {
           assert_false(cache_exists,
                        'CacheStorage names should be not be converted.');
         });
   }, 'CacheStorage names are DOMStrings not USVStrings');
 
 done();