Make the WebSocket fail messages meaningful

Source/modules/websockets/MainThreadWebSocketChannel.h

Index: Source/modules/websockets/MainThreadWebSocketChannel.h
diff --git a/Source/modules/websockets/MainThreadWebSocketChannel.h b/Source/modules/websockets/MainThreadWebSocketChannel.h
index 83c83a6fe13f371c25a652943c3eab311534469a..4f5a49917142e54611ae8f2af3aec7e043770e05 100644
--- a/Source/modules/websockets/MainThreadWebSocketChannel.h
+++ b/Source/modules/websockets/MainThreadWebSocketChannel.h
@@ -32,6 +32,7 @@
 #define MainThreadWebSocketChannel_h
 
 #include "core/fileapi/FileReaderLoaderClient.h"
+#include "core/inspector/ScriptCallFrame.h"
 #include "core/platform/Timer.h"
 #include "core/platform/network/SocketStreamHandleClient.h"
 #include "modules/websockets/WebSocketChannel.h"
@@ -197,6 +198,7 @@ private:
     OwnPtr<FileReaderLoader> m_blobLoader;
     BlobLoaderStatus m_blobLoaderStatus;
 
+    ScriptCallFrame m_callFrameAtConnection;
     WebSocketDeflateFramer m_deflateFramer;
 };