Include animations and transitions in the cascade

Instead of applying animations and transitions to styled elements,
include them in the cascade. This allows them to interact properly with
things like font-size and !important rules.

components/style/traversal.rs

@@ -613,6 +613,7 @@ where
                         &new_styles.primary,
                         Some(&mut target),
                         traversal_data.current_dom_depth,
+                        &context.shared,
                     );
 
                     new_styles
@@ -669,6 +670,7 @@ where
                     &new_styles.primary,
                     None,
                     traversal_data.current_dom_depth,
+                    &context.shared,
                 );
             }