This is behind a pref and not enabled by default yet.
MozReview-Commit-ID: HKbP02PkdI9
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extra : rebase_source : 8f22436042684a2105c1a4e65d108ec0529903e1
Note that the default values of the prefs are chosen so as to preserve
existing behaviour.
The patch also updates a user-visible warning message, which was
already out of date as of bug 1274991.
MozReview-Commit-ID: AqBBoIucShT
--HG--
extra : rebase_source : 9750899e35829dc5388f575dd56c2c888ec6ea99
Implement this unil function to improve readability
MozReview-Commit-ID: FLKOGyq180W
--HG--
extra : rebase_source : db8dbc67dbc63c19df806e79ea36016d3d5fc8b6
extra : source : 47fa0a1f03acd6007e2d40e4ec5bc0ddba221361
Even for very small layers we want to avoid doing work on the main
thread.
At the same time, however, increase the minimum active layer size for
animations which come from restyles. These involve the main thread
anyway, so there is less to be gained from using an active
layer. Since switching items between active and inactive can have
large knock-on effects, we want to make sure it really is worth making
the layer active.
MozReview-Commit-ID: 8N6xlVW4Dp3
--HG--
extra : rebase_source : bd9a97899faaf187e5e148126711bb0ff5a29ee6
