Shadow DOM should be able to be disabled per context.

• Component: DOM
• Status: RESOLVED WONTFIX

[Hajime Morrita]

Basically this disables reverts http://trac.webkit.org/changeset/131549
because Chromium wants to temporally disable it.

[Hajime Morrita]

Created attachment 172254 [details]
Patch

[WebKit Review Bot]

Comment on attachment 172254 [details]
Patch

Clearing flags on attachment: 172254

Committed r133429: <http://trac.webkit.org/changeset/133429>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[Ojan Vafai]

This patch looks like it caused a bunch of perf/memory regressions:

http://build.chromium.org/f/chromium/perf/mac-release-10.6-webkit-latest/dom_perf/report.html?rev=166198&graph=CreateNodes&history=100

http://build.chromium.org/f/chromium/perf/mac-release-10.6-webkit-latest/intl1/report.html?rev=166182&graph=V8.MemoryHeapSampleTotalUsed_0.75&trace=V8.MemoryHeapSampleTotalUsed_0.75&history=150

http://build.chromium.org/f/chromium/perf/chromium-rel-win7-webkit/intl2/report.html?rev=165925&graph=ws_single_peak_r&history=100

The only other patch in the regression range was rolled out in https://bugs.webkit.org/show_bug.cgi?id=101533 and the regression didn't go away. 

It's hard for me to see where the regression would come from. The only thing I can think of is maybe the implementation of V8EnabledPerContext versus V8EnabledAtRuntime? That's just a wild guess.

Is it possible at this point to do a rollback so we can be 100% sure it was this patch?

[Shinya Kawanaka]

Can we think that regression comes from chromium side instead of WebKit side?
This is also a wild guess, though.

[Ojan Vafai]

(In reply to comment #5)
> Can we think that regression comes from chromium side instead of WebKit side?
> This is also a wild guess, though.

I considered that, but on the non-webkit canary bots, the same regression happened when this webkit revision was pulled into chromium deps and not at the same chromium revisions as on the webkit canary bots. So, I don't see how it could be a chromium side change. It's certainly possible I got confused and misread the graphs though. Feel free to double-check my conclusions. :)

[Shinya Kawanaka]

Hmm... I would like to hear morrita's comment.

[Dimitri Glazkov (Google)]

Reverted r133429 for reason:

Speculative roll out, investigating perf regression.

Committed r133904: <http://trac.webkit.org/changeset/133904>

[Ojan Vafai]

Looks like this was the cause of the regression. All the graphs listed have recovered their losses.

[Hajime Morrita]

This was rolled out at r133904 and we have no plan to land this again. Closing.