Remove outdated FIXME

Source/core/layout/LayoutObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 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 825 matching lines @@
         TextDecorationStyle style;
         AppliedTextDecoration() : color(Color::transparent), style(TextDecorationStyleSolid) { }
     };
 
     void getTextDecorations(unsigned decorations, AppliedTextDecoration& underline, AppliedTextDecoration& overline, AppliedTextDecoration& linethrough, bool quirksMode = false, bool firstlineStyle = false);
 
     // Return the LayoutBoxModelObject in the container chain which is responsible for painting this object, or 0
     // if painting is root-relative. This is the container that should be passed to the 'forPaintInvalidation'
     // methods.
     const LayoutBoxModelObject* containerForPaintInvalidation() const;
+    const LayoutBoxModelObject& containerForPaintInvalidationOnRootedTree() const;
     const LayoutBoxModelObject* adjustCompositedContainerForSpecialAncestors(const LayoutBoxModelObject* paintInvalidationContainer) const;
     bool isPaintInvalidationContainer() const;
 
     LayoutRect computePaintInvalidationRect()
     {
         return computePaintInvalidationRect(containerForPaintInvalidation());
     }
 
     // Returns the paint invalidation rect for this LayoutObject in the coordinate space of the paint backing (typically a GraphicsLayer) for |paintInvalidationContainer|.
     LayoutRect computePaintInvalidationRect(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = 0) const;
 
     // Returns the rect bounds needed to invalidate the paint of this object, in the coordinate space of the layoutObject backing of |paintInvalidationContainer|
     LayoutRect boundsRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* = 0) const;
 
     // Actually do the paint invalidate of rect r for this object which has been computed in the coordinate space
     // of the GraphicsLayer backing of |paintInvalidationContainer|. Note that this coordinaten space is not the same
     // as the local coordinate space of |paintInvalidationContainer| in the presence of layer squashing.
-    // If |paintInvalidationContainer| is 0, invalidate paints via the view.
-    // FIXME: |paintInvalidationContainer| should never be 0. See crbug.com/363699.

[Julien - ping for review, 2015/06/03 21:10:12]

Great that you're updating this comment!

The long-term goal is for this function to die, replaced by
containerForPaintInvalidationOnRootedTree() and it would be nice to put a
comment along these lines.

-    void invalidatePaintUsingContainer(const LayoutBoxModelObject* paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason) const;
+    void invalidatePaintUsingContainer(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason) const;
 
     // Invalidate the paint of a specific subrectangle within a given object. The rect |r| is in the object's coordinate space.
     void invalidatePaintRectangle(const LayoutRect&) const;
     void invalidatePaintRectangleNotInvalidatingDisplayItemClients(const LayoutRect& r) const { invalidatePaintRectangleInternal(r); }
 
     // Walk the tree after layout issuing paint invalidations for layoutObjects that have changed or moved, updating bounds that have changed, and clearing paint invalidation state.
     virtual void invalidateTreeIfNeeded(PaintInvalidationState&);
 
     virtual void invalidatePaintForOverflow();
     void invalidatePaintForOverflowIfNeeded();
@@ skipping 346 matching lines @@
 
     inline void invalidateSelectionIfNeeded(const LayoutBoxModelObject&, PaintInvalidationReason);
 
     inline void invalidateContainerPreferredLogicalWidths();
 
     void clearMayNeedPaintInvalidation();
 
     void setLayoutDidGetCalledSinceLastFrame();
     void clearLayoutDidGetCalledSinceLastFrame() { m_bitfields.setLayoutDidGetCalledSinceLastFrame(false); }
 
-    void invalidatePaintIncludingNonCompositingDescendantsInternal(const LayoutBoxModelObject* repaintContainer);
+    void invalidatePaintIncludingNonCompositingDescendantsInternal(const LayoutBoxModelObject& repaintContainer);
 
     LayoutRect previousSelectionRectForPaintInvalidation() const;
     void setPreviousSelectionRectForPaintInvalidation(const LayoutRect&);
 
     const LayoutBoxModelObject* enclosingCompositedContainer() const;
 
     LayoutFlowThread* locateFlowThreadContainingBlock() const;
     void removeFromLayoutFlowThread();
     void removeFromLayoutFlowThreadRecursive(LayoutFlowThread*);
 
@@ skipping 422 matching lines @@
 void showTree(const blink::LayoutObject*);
 void showLineTree(const blink::LayoutObject*);
 void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 void showLayoutTree(const blink::LayoutObject* object1, const blink::LayoutObject* object2);
 
 #endif
 
 #endif // LayoutObject_h