<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">On Feb 15, 2014, at 4:07 PM, Ryosuke Niwa <<a href="mailto:rniwa@webkit.org">rniwa@webkit.org</a>> wrote:<br class=""><div><br class="Apple-interchange-newline"><blockquote type="cite"><div class=""><div dir="ltr" class=""><div class="">Hi all,</div><div class=""><br class=""></div><div class="">Now that we've removed all of the existing shadow DOM implementations from trunk in <a href="http://trac.webkit.org/changeset/164131" class="">http://trac.webkit.org/changeset/164131</a>, I'm intending to work on new web components implementations in a branch based on the feedback Apple has given on public-webapps and www-style in near future, probably starting with custom elements.</div>
<div class=""><br class=""></div><div class="">I'd like to implement them in a branch to not inadvertently introduce performance regressions. The old implementation on trunk resulted in 5% overall slowdown in the page load time but we didn't quantify that until we removed the feature entirely last year. That's probably because the feature was added over years as a pile of small changesets each of which introduced immeasurably small performance regressions. Development in a branch allows a faithful performance comparison between the two.</div>
</div></div></blockquote><br></div><div>This is great news!</div><br class=""><div>All jokes aside, these are exciting features, but it’s important that we’re honest with ourselves about overall engine impact.</div><div><br></div><div>-Kling</div></body></html>