Mac color: Apply Sierra workaround unconditionally

ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm

Index: ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm
diff --git a/ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm b/ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm
index 05d85c50ecec16f96a2f71aea4615589daf2f101..187983ca1730c97211c0970266d952744ff4f7bf 100644
--- a/ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm
+++ b/ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm
@@ -63,7 +63,7 @@
   }
   if (!pending_ca_renderer_layer_tree_)
     pending_ca_renderer_layer_tree_.reset(new CARendererLayerTree(
-        allow_av_sample_buffer_display_layer_, base::mac::IsAtLeastOS10_12()));
+        allow_av_sample_buffer_display_layer_, false));
   return pending_ca_renderer_layer_tree_.get();
 }