IndexedDB: Various C++11isms and cleanup

Source/modules/indexeddb/IDBTransaction.h

Index: Source/modules/indexeddb/IDBTransaction.h
diff --git a/Source/modules/indexeddb/IDBTransaction.h b/Source/modules/indexeddb/IDBTransaction.h
index c269707227ee6a37b57c8941e1c71d2be08755b0..4e34e54d128422bb324c2b11e765d48009b384e7 100644
--- a/Source/modules/indexeddb/IDBTransaction.h
+++ b/Source/modules/indexeddb/IDBTransaction.h
@@ -119,14 +119,14 @@ private:
         Finished, // No more events will fire and no new requests may be filed.
     };
 
-    int64_t m_id;
+    const int64_t m_id;
     Member<IDBDatabase> m_database;
     const HashSet<String> m_objectStoreNames;
     Member<IDBOpenDBRequest> m_openDBRequest;
     const WebIDBTransactionMode m_mode;
-    State m_state;
-    bool m_hasPendingActivity;
-    bool m_contextStopped;
+    State m_state = Active;
+    bool m_hasPendingActivity = true;
+    bool m_contextStopped = false;
     Member<DOMError> m_error;
 
     HeapListHashSet<Member<IDBRequest>> m_requestList;
@@ -134,11 +134,8 @@ private:
     typedef HeapHashMap<String, Member<IDBObjectStore>> IDBObjectStoreMap;
     IDBObjectStoreMap m_objectStoreMap;
 
-    typedef HeapHashSet<Member<IDBObjectStore>> IDBObjectStoreSet;
-    IDBObjectStoreSet m_deletedObjectStores;
-
-    typedef HeapHashMap<Member<IDBObjectStore>, IDBObjectStoreMetadata> IDBObjectStoreMetadataMap;
-    IDBObjectStoreMetadataMap m_objectStoreCleanupMap;
+    HeapHashSet<Member<IDBObjectStore>> m_deletedObjectStores;
+    HeapHashMap<Member<IDBObjectStore>, IDBObjectStoreMetadata> m_objectStoreCleanupMap;
     IDBDatabaseMetadata m_previousMetadata;
 };