Clean compositing inputs for location APIs for sticky-affected elements.

third_party/WebKit/Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1652 matching lines @@
   void SetWillChangeContents(bool b) {
     SET_NESTED_VAR(rare_non_inherited_data_, will_change_, contents_, b);
   }
   void SetWillChangeScrollPosition(bool b) {
     SET_NESTED_VAR(rare_non_inherited_data_, will_change_, scroll_position_, b);
   }
   void SetSubtreeWillChangeContents(bool b) {
     SET_VAR(rare_inherited_data_, subtree_will_change_contents_, b);
   }
 
+  // sticky, TODO(smcgruer): Move?
+  bool IsInStickySubtree() const {
+    return rare_inherited_data_->is_in_sticky_subtree_;
+  }
+  void SetIsInStickySubtree(bool b) {
+    SET_VAR(rare_inherited_data_, is_in_sticky_subtree_, b);

[flackr, 2017/04/26 15:08:00]

Does setting this property, even if to false, mean that we always create the
rare inerited properties? Maybe we need to avoid creating it if b == false?

[smcgruer, 2017/04/26 17:45:45]

As discussed, SET_VAR only creates a new rare inherited data for a given node if
the value set is different from the parent value. Otherwise it just reuses the
parent rare inherited data.

+  }
+
   // z-index
   int ZIndex() const { return box_->ZIndex(); }
   bool HasAutoZIndex() const { return box_->HasAutoZIndex(); }
   void SetZIndex(int v) {
     SET_VAR(box_, has_auto_z_index_, false);
     SET_VAR(box_, z_index_, v);
   }
   void SetHasAutoZIndex() {
     SET_VAR(box_, has_auto_z_index_, true);
     SET_VAR(box_, z_index_, 0);
@@ skipping 2058 matching lines @@
       PseudoBitsInternal() | 1 << (pseudo - kFirstPublicPseudoId)));
 }
 
 inline bool ComputedStyle::HasPseudoElementStyle() const {
   return PseudoBitsInternal() & kElementPseudoIdMask;
 }
 
 }  // namespace blink
 
 #endif  // ComputedStyle_h