Update PaintLayer::needsPaintPhase flags when layer self-painting status changes

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 2445 matching lines @@
 }
 
 void PaintLayer::updateSelfPaintingLayer()
 {
     bool isSelfPaintingLayer = shouldBeSelfPaintingLayer();
     if (this->isSelfPaintingLayer() == isSelfPaintingLayer)
         return;
 
     m_isSelfPaintingLayer = isSelfPaintingLayer;
 
-    if (parent())
-        parent()->dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
+    if (PaintLayer* parent = this->parent()) {

[pdr., 2016/04/19 21:17:57]

The tests in this patch seem to pass without this code change.

[Xianzhu, 2016/04/19 23:35:47]

Thanks for verifying the tests. Sorry for not verifying by myself. Thought the
tests work.

Removed the floating object because we force layout when the floating object's
ancestor changes self-painting status.

Verified this time :)

+        parent->dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
+
+        if (PaintLayer* enclosingSelfPaintingLayer = parent->enclosingSelfPaintingLayer()) {
+            if (isSelfPaintingLayer)
+                mergeNeedsPaintPhaseFlagsFrom(*enclosingSelfPaintingLayer);
+            else
+                enclosingSelfPaintingLayer->mergeNeedsPaintPhaseFlagsFrom(*this);
+        }
+    }
 }
 
 PaintLayer* PaintLayer::enclosingSelfPaintingLayer()
 {
     PaintLayer* layer = this;
     while (layer && !layer->isSelfPaintingLayer())
         layer = layer->parent();
     return layer;
 }
 
@@ skipping 455 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif