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

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

Index: third_party/WebKit/Source/core/style/ComputedStyle.h
diff --git a/third_party/WebKit/Source/core/style/ComputedStyle.h b/third_party/WebKit/Source/core/style/ComputedStyle.h
index 840807efafc28841032b7312a96c91a507dffabf..c296c59a39f1f321e719177fb3070a9128c7b82b 100644
--- a/third_party/WebKit/Source/core/style/ComputedStyle.h
+++ b/third_party/WebKit/Source/core/style/ComputedStyle.h
@@ -1670,6 +1670,14 @@ class CORE_EXPORT ComputedStyle : public ComputedStyleBase,
     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(); }