Invalidate objects when containing block changed

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 869 matching lines @@
         if (paintInvalidationContainerSkipped && object == paintInvalidationContainer)
             *paintInvalidationContainerSkipped = true;
     }
     return nullptr;
 }
 
 LayoutBlock* LayoutObject::containerForFixedPosition(const LayoutBoxModelObject* paintInvalidationContainer, bool* paintInvalidationContainerSkipped) const
 {
     ASSERT(!paintInvalidationContainerSkipped || !*paintInvalidationContainerSkipped);
     ASSERT(!isText());
-    ASSERT(style()->position() == FixedPosition);
 
     LayoutObject* ancestor = parent();
     for (; ancestor && !ancestor->canContainFixedPositionObjects(); ancestor = ancestor->parent()) {
         if (paintInvalidationContainerSkipped && ancestor == paintInvalidationContainer)
             *paintInvalidationContainerSkipped = true;
     }
 
     ASSERT(!ancestor || !ancestor->isAnonymousBlock());
     return toLayoutBlock(ancestor);
 }
@@ skipping 2483 matching lines @@
             object.invalidateDisplayItemClients(m_paintInvalidationContainer, PaintInvalidationFull, nullptr);
         }
     private:
         const LayoutBoxModelObject& m_paintInvalidationContainer;
     };
 
     const LayoutBoxModelObject& paintInvalidationContainer = *paintInvalidationLayer->layoutObject();
     traverseNonCompositingDescendants(const_cast<LayoutObject&>(object), Functor(paintInvalidationContainer));
 }
 
-void LayoutObject::invalidatePaintOfPreviousPaintInvalidationRect(const LayoutBoxModelObject& paintInvalidationContainer, PaintInvalidationReason reason) const
+void LayoutObject::invalidatePaintOfPreviousPaintInvalidationRect(const LayoutBoxModelObject& paintInvalidationContainer, PaintInvalidationReason reason)
 {
     // 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);
 
     // The PaintController may have changed. Pass the previous paint invalidation rect to the new PaintController.
     // The rect will be updated if it changes during the next paint invalidation.
     invalidateDisplayItemClients(paintInvalidationContainer, PaintInvalidationLayer, &invalidationRect);
+
+    // This method may be used to invalidate paint of an object changing paint invalidation container.
+    // Clear previous paint invalidation rect on the original paint invalidation container to avoid
+    // under-invalidation if the new paint invalidation rect on the new paint invalidation container
+    // happens to be the same as the old one.
+    setPreviousPaintInvalidationRect(LayoutRect());
 }
 
 void LayoutObject::invalidatePaintIncludingNonCompositingDescendants()
 {
     class Functor : public LayoutObjectTraversalFunctor {
     public:
         explicit Functor(const LayoutBoxModelObject& paintInvalidationContainer) : m_paintInvalidationContainer(paintInvalidationContainer) { }
         void operator()(LayoutObject& object) const override
         {
             object.invalidatePaintOfPreviousPaintInvalidationRect(m_paintInvalidationContainer, PaintInvalidationLayer);
@@ skipping 95 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         fprintf(stderr, "Cannot showLayoutTree. Root is (nil)\n");
     }
 }
 
 #endif