Rename ExceptionCode constants to use the names in the spec (2/3)

Source/core/dom/MessagePort.cpp

Index: Source/core/dom/MessagePort.cpp
diff --git a/Source/core/dom/MessagePort.cpp b/Source/core/dom/MessagePort.cpp
index 37181e2ed905104613ebc438318fd46d336b6b1a..373cf52c0f66522f6d08168c1ef47cdfd46af76d 100644
--- a/Source/core/dom/MessagePort.cpp
+++ b/Source/core/dom/MessagePort.cpp
@@ -67,7 +67,7 @@ void MessagePort::postMessage(PassRefPtr<SerializedScriptValue> message, const M
         for (unsigned int i = 0; i < ports->size(); ++i) {
             MessagePort* dataPort = (*ports)[i].get();
             if (dataPort == this || m_entangledChannel->isConnectedTo(dataPort)) {
-                ec = INVALID_STATE_ERR;
+                ec = InvalidStateError;
                 return;
             }
         }