Revert of Second attempt to land change to remove NativeViewportService and

mojo/services/view_manager/ids.h

Index: mojo/services/view_manager/ids.h
diff --git a/mojo/services/view_manager/ids.h b/mojo/services/view_manager/ids.h
index 0d1c48644790c27ec3604117a514486dc0a2adf9..4a27c627b4e63db1a975e33ec213dfd6459520d6 100644
--- a/mojo/services/view_manager/ids.h
+++ b/mojo/services/view_manager/ids.h
@@ -7,6 +7,7 @@
 
 #include "mojo/services/public/cpp/view_manager/types.h"
 #include "mojo/services/public/cpp/view_manager/util.h"
+#include "mojo/services/view_manager/view_manager_export.h"
 
 namespace mojo {
 namespace service {
@@ -20,7 +21,7 @@
 const ConnectionSpecificId kWindowManagerConnection = 1;
 
 // Adds a bit of type safety to view ids.
-struct ViewId {
+struct MOJO_VIEW_MANAGER_EXPORT ViewId {
   ViewId(ConnectionSpecificId connection_id, ConnectionSpecificId view_id)
       : connection_id(connection_id),
         view_id(view_id) {}