1164744 - Associate layer transaction cost with dom element changes

Status: NEW

(Core :: Graphics, defect)

Description

[Peter Chang[:pchang]]

In gecko, the layer transaction happens usually because some dom element/style changes. Developers need to use gecko profiler to record restyle cause to find out why this layer transaction happens. Once we associate the layer transaction cost with the dom element/style changes, we can export this information to WebIDE to let app developers to know the cost of app changes.

Comment 1

[Peter Chang[:pchang]]

Just found there is a nsStyleChangeData[1] which will store the style changed Property on frame tree. I'm checking which elements are stored when style changes happens, comparing to mPendingStyles from RestyleManager. If it is exactly the data I want, I will try to modify this structure and save to a new struct 'render statistic' which could be used to export to gecko profiler, raptor and WebIDE.

[1]https://dxr.mozilla.org/mozilla-central/source/layout/base/nsStyleChangeList.h?from=nsStyleChangeData&case=true#23

Comment 2

[Peter Chang[:pchang]]

During the implementation,we might integrate this association with mozilla telemetry service to provide some histogram. Investigating how did telemetry work.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The bug assignee didn't login in Bugzilla in the last 7 months, so the assignee is being reset.