[SPInvalidation] Update paint properties on perspective etc. change

third_party/WebKit/Source/core/layout/LayoutBoxModelObject.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 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. 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 223 matching lines @@
 
   if (hasLayer() && diff.cssClipChanged())
     layer()->clipper().clearClipRectsIncludingDescendants();
 
   LayoutObject::styleWillChange(diff, newStyle);
 }
 
 DISABLE_CFI_PERF
 void LayoutBoxModelObject::styleDidChange(StyleDifference diff,
                                           const ComputedStyle* oldStyle) {
-  bool hadTransform = hasTransformRelatedProperty();
+  bool hadTransformRelatedProperty = hasTransformRelatedProperty();
   bool hadLayer = hasLayer();
   bool layerWasSelfPainting = hadLayer && layer()->isSelfPaintingLayer();
   bool wasFloatingBeforeStyleChanged =
       FloatStateForStyleChange::wasFloating(this);
   bool wasHorizontalWritingMode = isHorizontalWritingMode();
 
   LayoutObject::styleDidChange(diff, oldStyle);
   updateFromStyle();
 
   // When an out-of-flow-positioned element changes its display between block
@@ skipping 33 matching lines @@
     // Either a transform wasn't specified or the object doesn't support
     // transforms, so just null out the bit.
     setHasTransformRelatedProperty(false);
     setHasReflection(false);
     layer()->updateFilters(oldStyle, styleRef());
     layer()->updateClipPath(oldStyle, styleRef());
     // Calls destroyLayer() which clears m_layer.
     layer()->removeOnlyThisLayerAfterStyleChange();
     if (wasFloatingBeforeStyleChanged && isFloating())
       setChildNeedsLayout();
-    if (hadTransform)
+    if (hadTransformRelatedProperty) {
       setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(
           LayoutInvalidationReason::StyleChange);
+    }
     if (!needsLayout()) {
       // FIXME: We should call a specialized version of this function.
       parentLayer->updateLayerPositionsAfterLayout();
     }
   }
 
   if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
     // hasLayer status will affect whether to create localBorderBoxProperties.
-    if (hadLayer != hasLayer()) {
+    // hasTransformRelatedProperty will affect whether to create transform node.
+    if (hadLayer != hasLayer() ||
+        hadTransformRelatedProperty != hasTransformRelatedProperty()) {

[Xianzhu, 2016/12/16 23:06:16]

I haven't found a test case failing without the above change, perhaps because
there are other paths also setNeedsPaintPropertyUpdate() on change of
preserve-3d, will-change: transform, but I think this can be a fail-safe and is
consistent with what we do in property update.

       setNeedsPaintPropertyUpdate();
     } else if (oldStyle && oldStyle->position() != styleRef().position() &&
                (oldStyle->position() == FixedPosition ||
                 styleRef().position() == FixedPosition)) {
       // Fixed-position status affects whether to create paintOffsetTranslation.
       // TODO(chrishtr): Update the condition here when changing the condition
       // in PaintPropertyTreeBuilder::updatePaintOffsetTranslation().
       setNeedsPaintPropertyUpdate();
     }
   }
@@ skipping 1016 matching lines @@
   if (rootElementStyle->hasBackground())
     return false;
 
   if (node() != document().firstBodyElement())
     return false;
 
   return true;
 }
 
 }  // namespace blink