** some extra work needed to land pieces separately
** high cost of merging with other changes to the code
** [https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=b2aeb8be3ded first piece] and [https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=a5ee3b2e133a first second piece] landed
* pieces of off-main-thread animations landed / landing: {{bug|706179}}, {{bug|755084}}
** starting off with animating just transforms and opacity in the layer system
** still running style change handling on the main thread, just suppressing repainting (to be improved later, but tricky)
* other notable patches landed:
** {{bug|745148}}: Support content processes pushing layer transactions directly to off-main-thread compositor in parent process
==Media==