(and possibly MessageManager too) I'm looking at profiles of tab code where 13ms of a 50ms block is XPConnect overhead from frameloaders and webnavigation objects, which should drop to approximately 0 for WebIDL. Presumably this shows up in a lot of other places, too.

Splitting this into two bugs, since the docShell case is much more complicated.

Comment on attachment 8899195 [details] Bug 1391110: Part 4 - Remove unnecessary nsIFrameLoaderOwner QIs. https://reviewboard.mozilla.org/r/170466/#review175638

Comment on attachment 8899193 [details] Bug 1391110: Part 2 - Reparent FrameLoader wrapper when owner content changes. https://reviewboard.mozilla.org/r/170462/#review175640 scary.

Comment on attachment 8899194 [details] Bug 1391110: Part 3 - Add nsIWebBrowserPersistable to FrameLoader bindings. https://reviewboard.mozilla.org/r/170464/#review175642 ::: dom/base/nsFrameLoader.cpp:3878 (Diff revision 1) > } > } > > +void > +nsFrameLoader::StartPersistence(uint64_t aOuterWindowID, > + nsIWebBrowserPersistDocumentReceiver* aRecv, Could you align latter two params under the first one.

Btw, do you have links to some profiles where all this is showing up badly?

Comment on attachment 8899192 [details] Bug 1391110: Part 1 - Convert FrameLoader bindings to WebIDL. https://reviewboard.mozilla.org/r/170460/#review175644

(In reply to Olli Pettay [:smaug] from comment #9) > Btw, do you have links to some profiles where all this is showing up badly? Not for most of them (perf-html links are hard to keep track of), but here's the most relevant one for frameloader performance in my recent history: https://perfht.ml/2vjtOLR Which is based on a testcase add-on replicating the performance issues from bug 1385618. They also show up in Andy's profiles in that bug (comment 6), particularly the WebNavigation issues: https://perfht.ml/2v0SEVg

https://hg.mozilla.org/integration/mozilla-inbound/rev/6763889f2682541de1443960bb1e0e0785a7491a Bug 1391110: Part 1 - Convert FrameLoader bindings to WebIDL. r=smaug https://hg.mozilla.org/integration/mozilla-inbound/rev/44dfa6fc4ba628358ef1fa51cdd400dabf68deb2 Bug 1391110: Part 2 - Reparent FrameLoader wrapper when owner content changes. r=smaug https://hg.mozilla.org/integration/mozilla-inbound/rev/5a801710d5f2daa3cc19f1b13c37900b5a594b7c Bug 1391110: Part 3 - Add nsIWebBrowserPersistable to FrameLoader bindings. r=smaug https://hg.mozilla.org/integration/mozilla-inbound/rev/4b9198e1725289baac765a7b0398ff97db87da38 Bug 1391110: Part 4 - Remove unnecessary nsIFrameLoaderOwner QIs. r=smaug

https://hg.mozilla.org/mozilla-central/rev/6763889f2682 https://hg.mozilla.org/mozilla-central/rev/44dfa6fc4ba6 https://hg.mozilla.org/mozilla-central/rev/5a801710d5f2 https://hg.mozilla.org/mozilla-central/rev/4b9198e17252