Change mojo enums to be scoped enums in the generated C++ bindings.

mojo/services/network/http_connection_impl.cc

Index: mojo/services/network/http_connection_impl.cc
diff --git a/mojo/services/network/http_connection_impl.cc b/mojo/services/network/http_connection_impl.cc
index 21c2f3767abc6e014c184747da8a7cc155e02a2d..b2c7fd1d8984acb2481f913f4e2623d323c64f5f 100644
--- a/mojo/services/network/http_connection_impl.cc
+++ b/mojo/services/network/http_connection_impl.cc
@@ -156,7 +156,7 @@ class HttpConnectionImpl::WebSocketImpl : public WebSocket {
   }
 
   void Send(bool fin, MessageType type, uint32_t num_bytes) override {
-    if (!fin || type != MESSAGE_TYPE_TEXT) {
+    if (!fin || type != MessageType::TEXT) {
       NOTIMPLEMENTED();
       Close();
     }
@@ -196,7 +196,7 @@ class HttpConnectionImpl::WebSocketImpl : public WebSocket {
       return;
 
     if (buffer)
-      client_->DidReceiveData(true, MESSAGE_TYPE_TEXT, num_bytes);
+      client_->DidReceiveData(true, MessageType::TEXT, num_bytes);
   }
 
   // Checks whether Close() has been called.