[webkit-reviews] review granted: [Bug 216355] Don't create event regions when the page has no subscrollers : [Attachment 408432] patch

[bugzilla-daemon at webkit.org]

Simon Fraser (smfr) <simon.fraser at apple.com> has granted Antti Koivisto
<koivisto at iki.fi>'s request for review:
Bug 216355: Don't create event regions when the page has no subscrollers
https://bugs.webkit.org/show_bug.cgi?id=216355

Attachment 408432: patch

https://bugs.webkit.org/attachment.cgi?id=408432&action=review




--- Comment #6 from Simon Fraser (smfr) <simon.fraser at apple.com> ---
Comment on attachment 408432
  --> https://bugs.webkit.org/attachment.cgi?id=408432
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=408432&action=review

> Source/WebCore/page/scrolling/ScrollingStateScrollingNode.cpp:39
> +    scrollingStateTree().scrollingNodeAdded();

I wonder if ScrollingStateTree::addNode() is a better place to call this.

> Source/WebCore/page/scrolling/ScrollingStateScrollingNode.cpp:80
> +    scrollingStateTree().scrollingNodeRemoved();

I wonder if ScrollingStateTree::willRemoveNode() is a better place to call
this.

>> Source/WebCore/rendering/RenderLayerCompositor.cpp:880
>> +		invalidateEventRegionForAllFrames();
> 
> I don't like that this triggers a second compositing update just after we've
finished one, and in all frames too!
> 
> This means that every page with one or more subscrollers now suffers from an
extra full layer tree walk in all frames and a second compositing update.

I see now that we'll update regions at the end of the rendering update.