Ashy-throated warbler, Grey-faced willow warbler
(Chích mày xám, Phylloscopus maculipennis)

The ashy-throated warbler (Phylloscopus maculipennis) is a species of leaf warbler (family Phylloscopidae). 

The name Phylloscopus combines the Ancient Greek phullon meaning "leaf" and skopos meaning "seeker" (from skopeo, "to watch").
maculipennis: Latin macula: spot, stain; -pennis: -winged (penna, pennae wing, feather).