style: Skip custom properties comparison if other inherited properties changed.

1 files changed, 10 insertions, 0 deletions

diff --git a/components/style/gecko/restyle_damage.rs b/components/style/gecko/restyle_damage.rs
index f325e7916ed..f8a43e8b7ea 100644
--- a/components/style/gecko/restyle_damage.rs
+++ b/components/style/gecko/restyle_damage.rs
@@ -57,6 +57,16 @@ impl GeckoRestyleDamage {
                 &mut reset_only,
             )
         };
+        if reset_only &&
+           old_style.custom_properties() != new_style.custom_properties() {
+            // The Gecko_CalcStyleDifference call only checks the non-custom
+            // property structs, so we check the custom properties here. Since
+            // they generate no damage themselves, we can skip this check if we
+            // already know we had some inherited (regular) property
+            // differences.
+            any_style_changed = true;
+            reset_only = false;
+        }
         let change = if any_style_changed {
             StyleChange::Changed { reset_only }
         } else {