Invalidate non-self-painting-layer descendants when creating a layer

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 2499b0365de08b2b19824780c8af16bcf705f6f5..b8d65b7f480d8e5b8a55f30451ddfa60ae3fde97 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -3388,6 +3388,18 @@ void LayoutObject::invalidateDisplayItemClientForNonCompositingDescendantsOf(con
     traverseNonCompositingDescendants(const_cast<LayoutObject&>(object), Functor(paintInvalidationContainer));
 }
 
+void LayoutObject::invalidatePaintOfPreviousPaintInvalidationRect(const LayoutBoxModelObject& paintInvalidationContainer, PaintInvalidationReason reason) const
+{
+    // These disablers are valid because we want to use the current compositing/invalidation status.
+    DisablePaintInvalidationStateAsserts invalidationDisabler;
+    DisableCompositingQueryAsserts compositingDisabler;
+
+    LayoutRect invalidationRect = previousPaintInvalidationRect();
+    adjustInvalidationRectForCompositedScrolling(invalidationRect, paintInvalidationContainer);
+    invalidatePaintUsingContainer(paintInvalidationContainer, invalidationRect, PaintInvalidationLayer);
+    invalidateDisplayItemClients(paintInvalidationContainer, PaintInvalidationLayer, invalidationRect, invalidationRect);
+}
+
 void LayoutObject::invalidatePaintIncludingNonCompositingDescendants()
 {
     class Functor : public LayoutObjectTraversalFunctor {
@@ -3395,10 +3407,8 @@ void LayoutObject::invalidatePaintIncludingNonCompositingDescendants()
         explicit Functor(const LayoutBoxModelObject& paintInvalidationContainer) : m_paintInvalidationContainer(paintInvalidationContainer) { }
         void operator()(LayoutObject& object) const override
         {
-            LayoutRect invalidationRect = object.previousPaintInvalidationRect();
-            object.adjustInvalidationRectForCompositedScrolling(invalidationRect, m_paintInvalidationContainer);
-            object.invalidatePaintUsingContainer(m_paintInvalidationContainer, invalidationRect, PaintInvalidationLayer);
-            object.invalidateDisplayItemClients(m_paintInvalidationContainer, PaintInvalidationLayer, invalidationRect, invalidationRect);
+            object.invalidatePaintOfPreviousPaintInvalidationRect(m_paintInvalidationContainer, PaintInvalidationLayer);
+            object.setPreviousPaintInvalidationRect(LayoutRect());
         }
     private:
         const LayoutBoxModelObject& m_paintInvalidationContainer;
@@ -3425,6 +3435,16 @@ void LayoutObject::setShouldDoFullPaintInvalidationIncludingNonCompositingDescen
     traverseNonCompositingDescendants(*this, Functor());
 }
 
+void LayoutObject::invalidatePaintIncludingNonSelfPaintingLayerDescendants(const LayoutBoxModelObject& paintInvalidationContainer)
+{
+    invalidatePaintOfPreviousPaintInvalidationRect(paintInvalidationContainer, PaintInvalidationLayer);
+    setPreviousPaintInvalidationRect(LayoutRect());

[Xianzhu, 2015/10/14 18:17:48]

I removed this line (and line 3411 above) because it caused wrong invalidation
when the object is removed later.

+    for (LayoutObject* child = slowFirstChild(); child; child = child->nextSibling()) {
+        if (!child->hasLayer() || !toLayoutBoxModelObject(child)->layer()->isSelfPaintingLayer())

[chrishtr, 2015/10/14 17:43:00]

Also non-compositing right? Non-self-painting paint layers can get composited
layers I think.

[Xianzhu, 2015/10/14 18:17:48]

I think all composited layers are self-painting, otherwise we'll paint them
twice on the parent composited layer (by layout object painter walk) and its own
composited layer (by CompositedLayerMapping::paintContents()).
PaintLayer::shouldBeSelfPaintingLayer() seems to ensure this.

+            child->invalidatePaintIncludingNonSelfPaintingLayerDescendants(paintInvalidationContainer);
+    }
+}
+
 void LayoutObject::setIsSlowRepaintObject(bool isSlowRepaintObject)
 {
     ASSERT(frameView());