[roll] Roll zircon a67f715..5dad829 (5 commits)

5dad829 [uapp] Add vsync mode to gfxlatency test
ee627b1 [dev][ethernet] Add support for Intel 82579LM.
52a1545 [fidl] Epitaph support.
9a9da6b [runtests] Add TMPDIR to environment variable whitelist.
820dd86 [ulib][xdc-host] Lib for connecting to xdc host.

Test: CQ

Change-Id: If93c6c11e1fca05d501f4227e1cfa3a020bb2c24
1 file changed