Reland main thread position sticky implementation.

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 347 matching lines @@
     m_widthAvailableToChildrenChanged |= oldStyle && diff.needsFullLayout() && needsLayout() && borderOrPaddingLogicalDimensionChanged(*oldStyle, newStyle, LogicalWidth);
     m_heightAvailableToChildrenChanged |= oldStyle && diff.needsFullLayout() && needsLayout() && borderOrPaddingLogicalDimensionChanged(*oldStyle, newStyle, LogicalHeight);
 }
 
 void LayoutBlock::updateFromStyle()
 {
     LayoutBox::updateFromStyle();
 
     bool shouldClipOverflow = !styleRef().isOverflowVisible() && allowsOverflowClip();
     if (shouldClipOverflow != hasOverflowClip()) {
+        if (!shouldClipOverflow)
+            getScrollableArea()->invalidateAllStickyConstraints();
+
         // FIXME: This shouldn't be required if we tracked the visual overflow
         // generated by positioned children or self painting layers. crbug.com/345403
         for (LayoutObject* child = firstChild(); child; child = child->nextSibling())
             child->setMayNeedPaintInvalidation();
     }
     setHasOverflowClip(shouldClipOverflow);
 }
 
 bool LayoutBlock::allowsOverflowClip() const
 {
@@ skipping 455 matching lines @@
                 PaintLayerScrollableArea* scrollableArea = block->layer()->getScrollableArea();
                 if (scrollMap)
                     scrollMap->add(scrollableArea, scrollableArea->scrollPositionDouble());
                 childrenMarkedForRelayout |= scrollableArea->updateAfterLayout(layoutScope);
             }
         }
     }
     return childrenMarkedForRelayout;
 }
 
-void LayoutBlock::updateScrollInfoAfterLayout()
+void LayoutBlock::updateAfterLayout()
 {
+    invalidateStickyConstraints();
+
+    // Update our scroll information if we're overflow:auto/scroll/hidden now that we know if
+    // we overflow or not.
     if (hasOverflowClip()) {
         if (style()->isFlippedBlocksWritingMode()) {
             // FIXME: https://bugs.webkit.org/show_bug.cgi?id=97937
             // Workaround for now. We cannot delay the scroll info for overflow
             // for items with opposite writing directions, as the contents needs
             // to overflow in that direction
             layer()->getScrollableArea()->updateAfterLayout();
             return;
         }
 
@@ skipping 222 matching lines @@
         // For now just always recompute overflow. This is no worse performance-wise than the old code that called rightmostPosition and
         // lowestPosition on every relayout so it's not a regression.
         // computeOverflow expects the bottom edge before we clamp our height. Since this information isn't available during
         // simplifiedLayout, we cache the value in m_overflow.
         LayoutUnit oldClientAfterEdge = hasOverflowModel() ? m_overflow->layoutClientAfterEdge() : clientLogicalBottom();
         computeOverflow(oldClientAfterEdge, true);
     }
 
     updateLayerTransformAfterLayout();
 
-    updateScrollInfoAfterLayout();
+    updateAfterLayout();
 
     clearNeedsLayout();
 
     if (LayoutAnalyzer* analyzer = frameView()->layoutAnalyzer())
         analyzer->increment(LayoutAnalyzer::LayoutObjectsThatNeedSimplifiedLayout);
 
     return true;
 }
 
 void LayoutBlock::markFixedPositionObjectForLayoutIfNeeded(LayoutObject* child, SubtreeLayoutScope& layoutScope)
@@ skipping 1728 matching lines @@
 void LayoutBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const LayoutObject* obj) const
 {
     showLayoutObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink