Skip PaintPhaseDescendantOutlinesOnly if no descendent outlines in the layer

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

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index df982ee3b772a6d2fc8da5b4bab1e45cf1824700..a2ac6e5f4483af3e5dc25420e575741009108940 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -127,6 +127,7 @@ PaintLayer::PaintLayer(LayoutBoxModelObject* layoutObject, PaintLayerType type)
     , m_lostGroupedMapping(false)
     , m_needsRepaint(false)
     , m_previousPaintResult(PaintLayerPainter::FullyPainted)
+    , m_needsPaintPhaseChildOutlines(false)
     , m_layoutObject(layoutObject)
     , m_parent(0)
     , m_previous(0)
@@ -945,6 +946,15 @@ PaintLayer* PaintLayer::enclosingLayerForPaintInvalidation() const
     return nullptr;
 }
 
+PaintLayer* PaintLayer::enclosingSelfPaintingLayer() const
+{
+    for (PaintLayer* layer = const_cast<PaintLayer*>(this); layer; layer = layer->parent()) {

[chrishtr, 2016/01/12 23:52:24]

should be compositingContainer() instead of parent() right?

[Xianzhu, 2016/01/13 00:11:03]

No. We just want to find the self painting layer which may be between this layer
and compositingContainer(). This won't violet paint order because if this layer
is self painting, the function returns this; otherwise the self painting layer
should definitely be the ancestor of this layer.

[chrishtr, 2016/01/13 05:01:17]

I see, ok.

+        if (layer->isSelfPaintingLayer())
+            return layer;
+    }
+    return nullptr;
+}
+
 void PaintLayer::setNeedsCompositingInputsUpdate()
 {
     m_needsAncestorDependentCompositingInputsUpdate = true;