Expand overloaded methods and optional parameters in the html library.

tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate

Index: tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate b/tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate
index fc77a04e9415a53deae83680e8e9ee18e1084e11..b58b364c7c7472e90d125615020e086a17b0ccd2 100644
--- a/tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate
+++ b/tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate
@@ -36,6 +36,31 @@ $if DART2JS
     return _transaction(storeName_OR_storeNames, mode);
   }
 
+  Transaction transactionStore(String storeName, String mode) {
+    if (mode != 'readonly' && mode != 'readwrite') {
+      throw new ArgumentError(mode);
+    }
+    // Try and create a transaction with a string mode.  Browsers that expect a
+    // numeric mode tend to convert the string into a number.  This fails
+    // silently, resulting in zero ('readonly').
+    return _transaction(storeName, mode);
+  }
+
+  Transaction transactionList(List<String> storeNames, String mode) {
+    if (mode != 'readonly' && mode != 'readwrite') {
+      throw new ArgumentError(mode);
+    }
+    List storeNames_1 = convertDartToNative_StringArray(storeNames);
+    return _transaction(storeNames_1, mode);
+  }
+  
+  Transaction transactionStores(DomStringList storeNames, String mode) {
+    if (mode != 'readonly' && mode != 'readwrite') {
+      throw new ArgumentError(mode);
+    }
+    return _transaction(storeNames_1, mode);
+  }
+
   @JSName('transaction')
   Transaction _transaction(stores, mode) native;
 $endif