Deactivate IDBTransactions created within Microtasks

LayoutTests/storage/indexeddb/microtasks.html

Index: LayoutTests/storage/indexeddb/microtasks.html
diff --git a/LayoutTests/storage/indexeddb/microtasks.html b/LayoutTests/storage/indexeddb/microtasks.html
index fb081715f5b4b950623537218a1c6864a1aa1674..b09c9d2f549b07e86dd0db5cc309340e16bd61a2 100644
--- a/LayoutTests/storage/indexeddb/microtasks.html
+++ b/LayoutTests/storage/indexeddb/microtasks.html
@@ -58,6 +58,30 @@ idb_test(
 );
 
 idb_test(
+    'Transactions created in microtasks resolved by host behavior are deactivated when control returns to the event loop',
+    function(t, db) {
+        db.createObjectStore('store');
+    },
+    function(t, db) {
+        var aesAlgorithmKeyGen = {name: "AES-CBC", length: 128};
+        crypto.subtle.generateKey(aesAlgorithmKeyGen, false, ["encrypt"]).then(t.step_func(function() {
+            var tx = db.transaction('store');
+            var request = tx.objectStore('store').get(0);
+            request.onerror = t.unreached_func('request should not fail');
+            request.onsuccess = t.step_func(function() {
+                assert_true(isTransactionActive(tx, 'store'),
+                            'Transaction should be active during event dispatch');
+                setTimeout(t.step_func(function() {
+                    assert_false(isTransactionActive(tx, 'store'),
+                                 'Transaction should be inactive once control returns to event loop');
+                    t.done();
+                }), 0);
+            });
+        }));
+    }
+);
+
+idb_test(
     'Transactions created in microtasks remain active in subsequent microtasks',
     function(t, db) {
         db.createObjectStore('store');