reed@ can we get someone to fix this simple issue? I'd do it but it probably isn't worth my time to setup a build env for skia cause it is so simple.

+herb... I added Mike when I filed this bug but hasn't been any traction. Herb is this something you can fix? Should either be a simple cast in GrResourceKey.h or changing operator[](int) to operator[](size_t) in SkTemplates.h

The following revision refers to this bug:
  https://skia.googlesource.com/skia/+/880979f32ca58acacbf676a7a6091fbb36dd520c

commit 880979f32ca58acacbf676a7a6091fbb36dd520c
Author: Herb Derby <herb@google.com>
Date: Tue Dec 18 01:11:02 2018

Fix 64-bit truncate warning

BUG= chromium:910360 

Change-Id: Ibd353d851626cca1b44bcfe38de5039a772bc6f0
Reviewed-on: https://skia-review.googlesource.com/c/178284
Auto-Submit: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>

[modify] https://crrev.com/880979f32ca58acacbf676a7a6091fbb36dd520c/include/gpu/GrResourceKey.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fa0d1b79b1522f6cab7e3e3e780c8095cf348031

commit fa0d1b79b1522f6cab7e3e3e780c8095cf348031
Author: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Date: Tue Dec 18 04:31:43 2018

Roll src/third_party/skia 5f178e721938..880979f32ca5 (3 commits)

https://skia.googlesource.com/skia.git/+log/5f178e721938..880979f32ca5


git log 5f178e721938..880979f32ca5 --date=short --no-merges --format='%ad %ae %s'
2018-12-18 herb@google.com Fix 64-bit truncate warning
2018-12-18 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2018-12-18 recipe-roller@chromium.org Roll recipe dependencies (trivial).


Created with:
  gclient setdep -r src/third_party/skia@880979f32ca5

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux-blink-rel;luci.chromium.try:linux-chromeos-compile-dbg;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel

BUG= chromium:910360 
TBR=halcanary@chromium.org

Change-Id: I99368de9df6729c55b398fe0930cdd89cdce3e35
Reviewed-on: https://chromium-review.googlesource.com/c/1381754
Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#617378}
[modify] https://crrev.com/fa0d1b79b1522f6cab7e3e3e780c8095cf348031/DEPS