The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1936d594c49632187c748ae028846562272e7538

commit 1936d594c49632187c748ae028846562272e7538
Author: Jonathan Backer <backer@chromium.org>
Date: Wed Apr 11 17:07:32 2018

Fix virtual contexts with RasterDecoder

Copy a few more lines from GLES2DecoderImpl. Tested by hand on Linux
desktop build with video, webgl, and canvas 2d.

Bug:  829438 
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I1d1edab35a7f418a2392a3dc1fa42aef4739d1c1
Reviewed-on: https://chromium-review.googlesource.com/1005786
Reviewed-by: Peng Huang <penghuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549914}
[modify] https://crrev.com/1936d594c49632187c748ae028846562272e7538/gpu/command_buffer/service/gles2_cmd_decoder.cc
[modify] https://crrev.com/1936d594c49632187c748ae028846562272e7538/gpu/command_buffer/service/raster_decoder.cc