undo CL 11967047 / d44f1df51f4d

rethinking about this

««« original CL description
go.talks: add support for mouse wheel interaction on the slides.

R=adg
CC=golang-dev
https://golang.org/cl/11967047
»»»

R=adg, r
CC=golang-dev
https://golang.org/cl/12217043
1 file changed