Change-Id: I2d3a1d002ad43af24cd8b451a2cae4c217482675 Reviewed-on: https://go-review.googlesource.com/1237 Reviewed-by: Andrew Gerrand <adg@golang.org>
Also update package webp to use package riff. LGTM=r R=r CC=golang-codereviews, pascal.massimino https://golang.org/cl/162850043