Split Dictionary's get and convert into DictionaryHelper.

Source/modules/indexeddb/IDBObjectStore.cpp

Index: Source/modules/indexeddb/IDBObjectStore.cpp
diff --git a/Source/modules/indexeddb/IDBObjectStore.cpp b/Source/modules/indexeddb/IDBObjectStore.cpp
index c7b46bab9b8d392fea5e37dae140ff933afb0480..fe21cab91159756191c57b2c40228c3d504f2677 100644
--- a/Source/modules/indexeddb/IDBObjectStore.cpp
+++ b/Source/modules/indexeddb/IDBObjectStore.cpp
@@ -386,10 +386,10 @@ private:
 IDBIndex* IDBObjectStore::createIndex(ScriptState* scriptState, const String& name, const IDBKeyPath& keyPath, const Dictionary& options, ExceptionState& exceptionState)
 {
     bool unique = false;
-    options.get("unique", unique);
+    DictionaryHelper::get(options, "unique", unique);
 
     bool multiEntry = false;
-    options.get("multiEntry", multiEntry);
+    DictionaryHelper::get(options, "multiEntry", multiEntry);
 
     return createIndex(scriptState, name, keyPath, unique, multiEntry, exceptionState);
 }