Remove indexed uniform buffer related code in RasterDecoder

RatserDecoder uses Skia to do rendering, and skia can restore indexed
uniform buffer, So we don't need maintain and restore it in RasterDecoder.

Bug: 902904
Change-Id: I234611646625a412d65bd632011ddd8e6647ca51
Reviewed-on: https://chromium-review.googlesource.com/c/1335733
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Peng Huang <penghuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608338}
2 files changed