DOM: Rename EventTarget#on() to EventTarget#when()
See the discussion in WICG/observable#39,
which led to this decision, and
WICG/observable#161 for the corresponding spec
rename.
R=jarhar
Bug: 40282760
Change-Id: I9cd744460a3545c74fb34a0418c6ffddc5e6d4e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5730072
Reviewed-by: Joey Arhar jarhar@chromium.org
Commit-Queue: Dominic Farolino dom@chromium.org
Cr-Commit-Position: refs/heads/main@{#1340875}