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 3cade6c3834ac9a0e4a9c29396feaf8e71ba5ea3..77aa9ae8b58f794ccb32895d757db1062d01ba98 100644
--- a/ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm
+++ b/ui/accelerated_widget_mac/ca_layer_tree_coordinator.mm
@@ -62,8 +62,9 @@
                    "specified, but not both.";
   }
   if (!pending_ca_renderer_layer_tree_)
-    pending_ca_renderer_layer_tree_.reset(new CARendererLayerTree(
-        allow_av_sample_buffer_display_layer_, base::mac::IsOSSierraOrLater()));
+    pending_ca_renderer_layer_tree_.reset(
+        new CARendererLayerTree(allow_av_sample_buffer_display_layer_,
+                                !base::mac::IsOSSierraOrLater()));
   return pending_ca_renderer_layer_tree_.get();
 }