Test WebGL2 on ANGLE's GL backed on Windows/NVIDIA.

testing/buildbot/chromium.gpu.fyi.json

 {
   "AAAAA1 AUTOGENERATED FILE DO NOT EDIT": {},
   "AAAAA2 See generate_buildbot_json.py to make changes": {},
   "Android Release (Nexus 5)": {
     "gtest_tests": [
       {
         "override_isolate_target": "angle_unittests",
         "swarming": {
           "can_use_on_swarming_builders": false,
           "cipd_packages": [
@@ skipping 16770 matching lines @@
             }
           ]
         }
       },
       {
         "args": [
           "webgl_conformance",
           "--show-stdout",
           "--browser=release",
           "-v",
+          "--extra-browser-args=--enable-logging=stderr --js-flags=--expose-gc --use-angle=gl",
+          "--webgl-conformance-version=2.0.1",
+          "--read-abbreviated-json-results-from=../../content/test/data/gpu/webgl2_conformance_tests_output.json"
+        ],
+        "isolate_name": "telemetry_gpu_integration_test",
+        "name": "webgl2_conformance_gl_tests",
+        "override_compile_targets": [
+          "telemetry_gpu_integration_test_run"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "gpu": "10de:104a",
+              "os": "Windows-2008ServerR2-SP1"
+            }
+          ],
+          "shards": 15
+        }
+      },
+      {
+        "args": [
+          "webgl_conformance",
+          "--show-stdout",
+          "--browser=release",
+          "-v",
           "--extra-browser-args=--enable-logging=stderr --js-flags=--expose-gc",
           "--webgl-conformance-version=2.0.1",
           "--read-abbreviated-json-results-from=../../content/test/data/gpu/webgl2_conformance_tests_output.json"
         ],
         "isolate_name": "telemetry_gpu_integration_test",
         "name": "webgl2_conformance_tests",
         "override_compile_targets": [
           "telemetry_gpu_integration_test_run"
         ],
         "swarming": {
@@ skipping 1138 matching lines @@
             {
               "gpu": "10de:104a",
               "os": "Windows-2008ServerR2-SP1"
             }
           ]
         }
       }
     ]
   }
 }