Invalidate objects when their content box changes dimensions.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 3808 matching lines @@
     }
 
     // If the transform is not identity or translation, incremental invalidation is not applicable
     // because the difference between oldBounds and newBounds doesn't cover all area needing invalidation.
     // FIXME: Should also consider ancestor transforms since paintInvalidationContainer. crbug.com/426111.
     if (invalidationReason == PaintInvalidationIncremental
         && paintInvalidationContainer != this
         && hasLayer() && layer()->transform() && !layer()->transform()->isIdentityOrTranslation())
         return PaintInvalidationBoundsChange;
 
+    if (style()->backgroundLayers().thisOrNextLayersUseContentBox() || style()->maskLayers().thisOrNextLayersUseContentBox() || style()->boxSizing() == BoxSizingBorderBox) {
+        LayoutRect oldContentBoxRect = m_rareData ? m_rareData->m_previousContentBoxRect : LayoutRect();
+        LayoutRect newContentBoxRect = contentBoxRect();
+        if (oldContentBoxRect != newContentBoxRect)
+            return PaintInvalidationContentBoxChange;
+    }
+
     if (!style()->hasBackground() && !style()->hasBoxDecorations()) {
         // We could let incremental invalidation cover non-composited scrollbars, but just
         // do a full invalidation because incremental invalidation will go away with slimming paint.
         if (invalidationReason == PaintInvalidationIncremental && hasNonCompositedScrollbars())
             return PaintInvalidationBorderBoxChange;
         return invalidationReason;
     }
 
-    if (style()->backgroundLayers().thisOrNextLayersUseContentBox() || style()->maskLayers().thisOrNextLayersUseContentBox()) {
-        LayoutRect oldContentBoxRect = m_rareData ? m_rareData->m_previousContentBoxRect : LayoutRect();
-        LayoutRect newContentBoxRect = contentBoxRect();
-        if (oldContentBoxRect != newContentBoxRect)
-            return PaintInvalidationContentBoxChange;
-    }
-
     if (style()->backgroundLayers().thisOrNextLayersHaveLocalAttachment()) {
         LayoutRect oldLayoutOverflowRect = m_rareData ? m_rareData->m_previousLayoutOverflowRect : LayoutRect();
         LayoutRect newLayoutOverflowRect = layoutOverflowRect();
         if (oldLayoutOverflowRect != newLayoutOverflowRect)
             return PaintInvalidationLayoutOverflowBoxChange;
     }
 
     LayoutSize oldBorderBoxSize = computePreviousBorderBoxSize(oldBounds.size());
     LayoutSize newBorderBoxSize = size();
 
@@ skipping 656 matching lines @@
     // If m_rareData is already created, always save.
     if (m_rareData)
         return true;
 
     LayoutSize paintInvalidationSize = previousPaintInvalidationRectSize();
     // Don't save old box sizes if the paint rect is empty because we'll
     // full invalidate once the paint rect becomes non-empty.
     if (paintInvalidationSize.isEmpty())
         return false;
 
+    // If we use border-box sizing we need to track changes in the size of the content box.
+    if (style()->boxSizing() == BoxSizingBorderBox)
+        return true;
+
     // We need the old box sizes only when the box has background, decorations, or masks.
     // Main LayoutView paints base background, thus interested in box size.
     if (!isLayoutView() && !style()->hasBackground() && !style()->hasBoxDecorations() && !style()->hasMask())
         return false;
 
     // No need to save old border box size if we can use size of the old paint
     // rect as the old border box size in the next invalidation.
     if (paintInvalidationSize != size())
         return true;
 
@@ skipping 222 matching lines @@
     if (!flowThread) {
         // If there's no flow thread, we're not nested. All pages have the same height. Give up.
         return strutToNextPage;
     }
     // Start searching for a suitable offset at the top of the next page or column.
     LayoutUnit flowThreadOffset = offsetFromLogicalTopOfFirstPage() + nextPageLogicalTop;
     return strutToNextPage + flowThread->nextLogicalTopForUnbreakableContent(flowThreadOffset, contentLogicalHeight) - flowThreadOffset;
 }
 
 } // namespace blink