[webkit-reviews] review denied: [Bug 109966] Early out of RenderLayer::updateCanBeStackingContainer more often : [Attachment 191080] Patch

[bugzilla-daemon at webkit.org]

Simon Fraser (smfr) <simon.fraser at apple.com> has denied Glenn Hartmann
<hartmanng at chromium.org>'s request for review:
Bug 109966: Early out of RenderLayer::updateCanBeStackingContainer more often
https://bugs.webkit.org/show_bug.cgi?id=109966

Attachment 191080: Patch
https://bugs.webkit.org/attachment.cgi?id=191080&action=review

------- Additional Comments from Simon Fraser (smfr) <simon.fraser at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=191080&action=review


> Source/WebCore/rendering/RenderBox.cpp:360
> +	       if (layer())
> +		  
layer()->dirtyAncestorStackingContextDescendantsAreContiguousInStackingOrder();


I think this should call a function on RenderLayer with a simpler name that
describes when it's called, but I can't tell from this call site what actually
matters.

> Source/WebCore/rendering/RenderLayer.cpp:710
> +    // Overflow are a box concept.

is a?

> Source/WebCore/rendering/RenderLayer.cpp:721
> +    bool overflowXHasChanged = overflowX == OSCROLL && (!oldStyle ||
oldStyle->overflowX() != OSCROLL);
> +    bool overflowYHasChanged = overflowY == OSCROLL && (!oldStyle ||
oldStyle->overflowY() != OSCROLL);
> +    if (overflowXHasChanged || overflowYHasChanged)
> +	  
dirtyAncestorStackingContextDescendantsAreContiguousInStackingOrder();

It's odd that you're dirtying a flag related to stacking order when overflow
changes. Sure, it's related to composited overflow, but you're making the
assumption that only composited overflow cares about the flag.

> Source/WebCore/rendering/RenderLayer.cpp:1140
> +	       ScopedNeedsCompositedScrollingUpdater(this);

This seems like an odd place for a Scope thing. Won't it be destroyed two lines
below?

> Source/WebCore/rendering/RenderLayer.h:1319
> +    RenderLayer* m_nextLayerToUpdateNeedsCompositedScrolling;
> +    RenderLayer* m_lastLayerToUpdateNeedsCompositedScrolling;

It seems wrong to take up space on RenderLayer with these.