Use typedef to shorten WorkerThreadableWebSocketChannel inner classes.

Source/modules/websockets/WorkerThreadableWebSocketChannel.h

Index: Source/modules/websockets/WorkerThreadableWebSocketChannel.h
diff --git a/Source/modules/websockets/WorkerThreadableWebSocketChannel.h b/Source/modules/websockets/WorkerThreadableWebSocketChannel.h
index 46cfa280b6dbd986f3a5f5de63cbab7412e6fd96..d5d7a84ec03ab87511869b1ba7c21bed4735ce0a 100644
--- a/Source/modules/websockets/WorkerThreadableWebSocketChannel.h
+++ b/Source/modules/websockets/WorkerThreadableWebSocketChannel.h
@@ -149,7 +149,6 @@ public:
 #endif
     };
 
-private:
     // Bridge for Peer. Running on the worker thread.
     class Bridge FINAL : public RefCountedWillBeGarbageCollectedFinalized<Bridge> {
     public:
@@ -196,6 +195,7 @@ private:
         WeakPtrWillBeWeakMember<Peer> m_peer;
     };
 
+private:
     WorkerThreadableWebSocketChannel(WorkerGlobalScope&, WebSocketChannelClient*, const String& sourceURL, unsigned lineNumber);
 
     const RefPtrWillBeMember<ThreadableWebSocketChannelClientWrapper> m_workerClientWrapper;