ngl: Avoid a coordinate overflow

This was showing up as big text selections going
missing sporadically.

Fixes: #4214

gsk/ngl/gsknglrenderjob.c

@@ -1408,7 +1408,10 @@ gsk_ngl_render_job_visit_color_node (GskNglRenderJob     *job,
   program = CHOOSE_PROGRAM (job, coloring);
   batch = gsk_ngl_command_queue_get_batch (job->command_queue);
 
-  if (batch->any.kind == GSK_NGL_COMMAND_KIND_DRAW &&
+  /* Limit the size, or we end up with a coordinate overflow somwhere. */
+  if (node->bounds.size.width < 300 &&
+      node->bounds.size.height < 300 &&
+      batch->any.kind == GSK_NGL_COMMAND_KIND_DRAW &&
       batch->any.program == program->id)
     {
       GskNglRenderOffscreen offscreen = {0};