Distinguish null IDBKey (no value) and invalid IDBKey (value is not valid key)

webkit/glue/idb_bindings.cc

Index: webkit/glue/idb_bindings.cc
diff --git a/webkit/glue/idb_bindings.cc b/webkit/glue/idb_bindings.cc
index ba9f592c61efddf4327d3dab336d6e72d3aa7307..13aa8e1ce932008894f5eebd1e182a6bb2c01140 100644
--- a/webkit/glue/idb_bindings.cc
+++ b/webkit/glue/idb_bindings.cc
@@ -25,13 +25,12 @@ bool IDBKeysFromValuesAndKeyPath(
     std::vector<WebIDBKey>* values) {
   WebIDBKeyPath web_idb_key_path = WebIDBKeyPath::create(idb_key_path);
   bool error = web_idb_key_path.parseError() != 0;
-  // TODO(bulach): what to do when we have a parse error? For now, setting
-  // all values back as invalid and returning a boolean.
+  // When a parse error is encountered, no value is returned (null)
   for (std::vector<WebSerializedScriptValue>::const_iterator i =
            serialized_script_values.begin();
        i != serialized_script_values.end(); ++i) {
     if (error) {
-      values->push_back(WebIDBKey::createInvalid());
+      values->push_back(WebIDBKey::createNull());
     } else {
       values->push_back(
           WebIDBKey::createFromValueAndKeyPath(*i, web_idb_key_path));