Switch GPU FYI XR Win Builder to builderless.

Add gpu-fyi-try-win-xr-builder as an alternative.

Drive-by remove non-existent
buildbot/chromium.gpu/Android Release (Nexus 5X)

Bug: 982086, 977735
Change-Id: I30effd28b414ce46df230c9b24305921c8cdb423
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1696691
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676613}

infra/config/cr-buildbucket.cfg

@@ -2308,11 +2308,9 @@ buckets {
       name: "GPU FYI Win x64 dEQP Builder"
       mixins: "win-gpu-fyi-ci"
     }
-    # Can't use builderless "win-gpu-fyi-ci" for perf bulder. crbug.com/977735
     builders {
       name: "GPU FYI XR Win Builder"
-      mixins: "win"
-      mixins: "gpu-fyi-ci"
+      mixins: "win-gpu-fyi-ci"
     }
     builders {
       name: "Win10 FYI Debug (NVIDIA)"
@@ -4406,6 +4404,10 @@ buckets {
     builders { mixins: "win-dawn-try" name: "dawn-win10-x64-deps-rel" }
     builders { mixins: "win-dawn-try" name: "dawn-win10-x86-deps-rel" }
 
+    builders {
+      mixins: "win-optional-gpu-try"
+      name: "gpu-fyi-try-win-xr-builder"
+    }
     builders {
       mixins: "win-optional-gpu-try"
       name: "gpu-fyi-try-win7-amd-dbg"

infra/config/luci-milo.cfg

@@ -3114,7 +3114,6 @@ consoles {
     category: "Linux"
   }
   builders {
-    name: "buildbot/chromium.gpu/Android Release (Nexus 5X)"
     name: "buildbucket/luci.chromium.ci/Android Release (Nexus 5X)"
     category: "Android"
   }
@@ -4449,6 +4448,9 @@ consoles {
   repo_url: "https://chromium.googlesource.com/chromium/src"
   refs: "refs/heads/master"
   manifest_name: "REVISION"
+  builders {
+    name: "buildbucket/luci.chromium.try/gpu-fyi-try-win-xr-builder"
+  }
   builders {
     name: "buildbucket/luci.chromium.try/gpu-fyi-try-win7-amd-dbg"
   }
@@ -4787,6 +4789,9 @@ consoles {
   builders {
     name: "buildbucket/luci.chromium.try/gpu-fyi-try-linux-nvidia-tsn"
   }
+  builders {
+    name: "buildbucket/luci.chromium.try/gpu-fyi-try-win-xr-builder"
+  }
   builders {
     name: "buildbucket/luci.chromium.try/gpu-fyi-try-win7-amd-dbg"
   }

tools/mb/mb_config.pyl

@@ -814,6 +814,7 @@
     },
 
     'tryserver.chromium.win': {
+      'gpu-fyi-try-win-xr-builder': 'gpu_fyi_tests_release_trybot_x86',
       'gpu-fyi-try-win7-amd-dbg': 'gpu_fyi_tests_debug_trybot_x86',
       'gpu-fyi-try-win7-amd-dqp': 'deqp_release_trybot_x86',
       'gpu-fyi-try-win7-amd-rel': 'gpu_fyi_tests_release_trybot_x86',