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

third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
@@ skipping 494 matching lines @@
     // SVG text layout code expects us to be a block-level style element.
     if ((isSVGForeignObjectElement(*element) || isSVGTextElement(*element)) &&
         style.IsDisplayInlineType())
       style.SetDisplay(EDisplay::kBlock);
 
     // Columns don't apply to svg text elements.
     if (isSVGTextElement(*element))
       style.ClearMultiCol();
   }
   AdjustStyleForAlignment(style, layout_parent_style);
+
+  // If this node is sticky it marks the creation of a sticky subtree, which we
+  // must track to properly handle document lifecycle in some cases.
+  //
+  // It is possible that this node is already in a sticky subtree (i.e. we have
+  // nested sticky nodes) - in that case the bit will already be set via
+  // inheritance from the ancestor and there is no harm to setting it again.
+  if (style.GetPosition() == EPosition::kSticky)
+    style.SetSubtreeIsSticky(true);
 }
 
 }  // namespace blink