1358405 - 13.97ms uninterruptible reflow at getComputedURL@chrome://browser/content/nsContextMenu.js:979:15

Status: NEW

(Firefox :: Menus, defect, P4)

Description

[hazel ward]

Here's the stack:

getComputedURL@chrome://browser/content/nsContextMenu.js:979:15
_setTargetForNodesWithChildren@chrome://browser/content/nsContextMenu.js:890:24
setTarget@chrome://browser/content/nsContextMenu.js:722:5
CM_initMenu@chrome://browser/content/nsContextMenu.js:70:5
nsContextMenu@chrome://browser/content/nsContextMenu.js:63:3
onpopupshowing@chrome://browser/content/browser.xul:1:119

Comment 1

[Florian Quèze [:florian]]

This is the code deciding if the element the user right clicked on to open the context menu has a background image: http://searchfox.org/mozilla-central/rev/7aa21f3b531ddee90a353215bd86e97d6974e25b/browser/base/content/nsContextMenu.js#890

I think this is another case where we would need a getComputedStyleWithoutFlushing.

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Since bug 1360406, the flush has been moved into the content process in ContextMenu.jsm:

https://searchfox.org/mozilla-central/rev/9f3bd430c2b132c86c46126a0548661de876799a/browser/modules/ContextMenu.jsm#384

It's still not great to flush like this, but thankfully, bug 1360406 made context menu handling async-y, which means that it should be possible to wait for the "natural" flush before returning the result to the parent.

Still, seeing as how this shouldn't really affect front-end performance (except in the rare cases where we're opening up context menu items on pages loaded in the parent process), I'm going to make this a qf:p3.