Facebook calls get_offsetWidth a bunch of times during load event handling

NEW
Unassigned

Status

()

P3
normal
a year ago
a year ago

People

(Reporter: jrmuizel, Unassigned)

Tracking

unspecified
Points:
---

Firefox Tracking Flags

(firefox57 wontfix)

Details

(Reporter)

Description

a year ago
See http://bit.ly/2wCqNvc

Facebook is doing 7 reflows when handling the load event. Is it possible for them to do better?
(Reporter)

Updated

a year ago
Flags: needinfo?(b56girard)
Facebook suggests that these reflows (from ViewportTrackingHelper) account for just 0.5% of our startup time in Chrome. Data does look suspiciously low to be fair.

Facebook could mitigate this by using the same layout flush to check all viewport tracking but that's not a simple change. There's also the option of using IntersectionObserver which is now shipping.
Flags: needinfo?(b56girard)
Priority: -- → P3
status-firefox57: --- → wontfix
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