Update list of tryservers that run GPU tests

# Docs update
No-Try: True

Bug: None
Change-Id: I06e79dd19bd049d854a1cedf6898b77d5568bbb7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1879719
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Auto-Submit: Kai Ninomiya <kainino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709685}

docs/gpu/gpu_testing.md

@@ -112,11 +112,11 @@ of the following tryservers' jobs:
 
 *   [linux-rel], formerly on the `tryserver.chromium.linux` waterfall
 *   [mac-rel], formerly on the `tryserver.chromium.mac` waterfall
-*   [win7-rel], formerly on the `tryserver.chromium.win` waterfall
+*   [win10_chromium_x64_rel_ng], formerly on the `tryserver.chromium.win` waterfall
 
-[linux-rel]:    https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux-rel?limit=100
-[mac-rel]:      https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac-rel?limit=100
-[win7-rel]:     https://ci.chromium.org/p/chromium/builders/luci.chromium.try/win7-rel?limit=100
+[linux-rel]:                 https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux-rel?limit=100
+[mac-rel]:                   https://ci.chromium.org/p/chromium/builders/luci.chromium.try/mac-rel?limit=100
+[win10_chromium_x64_rel_ng]: https://ci.chromium.org/p/chromium/builders/luci.chromium.try/win10_chromium_x64_rel_ng?limit=100
 
 Scan down through the steps looking for the text "GPU"; that identifies those
 tests run on the GPU bots. For each test the "trigger" step can be ignored; the