Only create sticky position constraints for constrained sticky position.

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 3009 matching lines @@
   // Position utility functions.
   bool HasOutOfFlowPosition() const {
     return GetPosition() == EPosition::kAbsolute ||
            GetPosition() == EPosition::kFixed;
   }
   bool HasInFlowPosition() const {
     return GetPosition() == EPosition::kRelative ||
            GetPosition() == EPosition::kSticky;
   }
   bool HasViewportConstrainedPosition() const {
-    return GetPosition() == EPosition::kFixed ||
-           GetPosition() == EPosition::kSticky;
+    return GetPosition() == EPosition::kFixed;
+  }
+  bool HasStickyConstrainedPosition() const {
+    return GetPosition() == EPosition::kSticky &&
+           (!Top().IsAuto() || !Left().IsAuto() || !Right().IsAuto() ||
+            !Bottom().IsAuto());
   }
 
   // Clip utility functions.
   const Length& ClipLeft() const { return visual_->clip.Left(); }
   const Length& ClipRight() const { return visual_->clip.Right(); }
   const Length& ClipTop() const { return visual_->clip.Top(); }
   const Length& ClipBottom() const { return visual_->clip.Bottom(); }
 
   // Offset utility functions.
   // Accessors for positioned object edges that take into account writing mode.
@@ skipping 669 matching lines @@
   pseudo_bits_ |= 1 << (pseudo - kFirstPublicPseudoId);
 }
 
 inline bool ComputedStyle::HasPseudoElementStyle() const {
   return pseudo_bits_ & kElementPseudoIdMask;
 }
 
 }  // namespace blink
 
 #endif  // ComputedStyle_h