(WIP) Invalidation during painting (for synchronized painting)

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 1897 matching lines @@
     // physical coordinate space of the paintInvalidationContainer.
     const ComputedStyle& styleToUse = styleRef();
 
     EPosition position = styleToUse.position();
 
     // We need to inflate the paint invalidation rect before we use paintInvalidationState,
     // else we would forget to inflate it for the current layoutObject. FIXME: If these were
     // included into the visual overflow for repaint, we wouldn't have this issue.
     inflatePaintInvalidationRectForReflectionAndFilter(rect);
 
-    if (paintInvalidationState && paintInvalidationState->canMapToContainer(ancestor) && position != FixedPosition) {
+    if (paintInvalidationState && paintInvalidationState->canMapToContainer(ancestor)
+        // We support fast path mapping to container for fixed-position in SPv2.
+        && (position != FixedPosition || RuntimeEnabledFeatures::slimmingPaintV2Enabled())) {
         if (layer() && layer()->transform())
             rect = LayoutRect(layer()->transform()->mapRect(pixelSnappedIntRect(rect)));
 
         // We can't trust the bits on LayoutObject, because this might be called while re-resolving style.
         if (styleToUse.hasInFlowPosition() && layer())
             rect.move(layer()->offsetForInFlowPosition());
 
         rect.moveBy(location());
         rect.move(paintInvalidationState->paintOffset());
         if (paintInvalidationState->isClipped())
@@ skipping 1891 matching lines @@
             return PaintInvalidationLayoutOverflowBoxChange;
     }
 
     LayoutSize oldBorderBoxSize = computePreviousBorderBoxSize(oldBounds.size());
     LayoutSize newBorderBoxSize = size();
 
     if (oldBorderBoxSize == newBorderBoxSize)
         return invalidationReason;
 
     // LayoutBox::incrementallyInvalidatePaint() depends on positionFromPaintInvalidationBacking
-    // which is not available when slimmingPaintOffsetCachingEnabled.
-    if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && (style()->hasBoxDecorations() || style()->hasBackground()))
+    // which is not available in SPv2.
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && (style()->hasBoxDecorations() || (style()->hasBackground() && hasVisualOverflow())))
         return PaintInvalidationBorderBoxChange;
 
     // TODO(wangxianzhu): Remove incremental invalidation when we remove rect-based paint invalidation.
     // See another hasNonCompositedScrollbars() callsite above.
     if (hasNonCompositedScrollbars())
         return PaintInvalidationBorderBoxChange;
 
     if (style()->hasVisualOverflowingEffect() || style()->hasAppearance() || style()->hasFilter() || style()->resize() != RESIZE_NONE)
         return PaintInvalidationBorderBoxChange;
 
@@ skipping 840 matching lines @@
 }
 
 void LayoutBox::IntrinsicSizingInfo::transpose()
 {
     size = size.transposedSize();
     aspectRatio = aspectRatio.transposedSize();
     std::swap(hasWidth, hasHeight);
 }
 
 } // namespace blink