Fixup for https://phabricator.services.mozilla.com/D255164

Signed-off-by: Oriol Brufau <[email protected]>

Author: Loirooriol

stylo_dom/lib.rs

@@ -5,7 +5,7 @@
 use bitflags::bitflags;
 use malloc_size_of::malloc_size_of_is_0;
 
-pub const HEADING_LEVEL_OFFSET: usize = 51;
+pub const HEADING_LEVEL_OFFSET: usize = 52;
 
 // DOM types to be shared between Rust and C++.
 bitflags! {
@@ -141,6 +141,8 @@ bitflags! {
         /// For :active-view-transition.
         /// <https://www.w3.org/TR/css-view-transitions-2/#the-active-view-transition-pseudo>
         const ACTIVE_VIEW_TRANSITION = 1u64 << 50;
+        /// For :-moz-suppress-for-print-selection.
+        const SUPPRESS_FOR_PRINT_SELECTION = 1u64 << 51;
         /// https://drafts.csswg.org/selectors-5/#headings
         /// These 4 bits are used to pack the elements heading level into the element state
         /// Heading levels can be from 1-9 so 4 bits allows us to express the full range.