Run telemetry_gpu_unittests via isolate on "Linux Tests" and trybot.

testing/buildbot/chromium.linux.json

Index: testing/buildbot/chromium.linux.json
diff --git a/testing/buildbot/chromium.linux.json b/testing/buildbot/chromium.linux.json
index 32f09c144a53dd83ae246e502f32c8ad61ed4a42..5dc8479ae8c79cf2067af27b18b5d3daa3406329 100644
--- a/testing/buildbot/chromium.linux.json
+++ b/testing/buildbot/chromium.linux.json
@@ -1009,6 +1009,12 @@
         "test": "wm_unittests"
       }
     ],
+    "isolated_scripts": [
+      {
+        "isolate_name": "telemetry_gpu_unittests",
+        "name": "telemetry_gpu_unittests"
+      }
+    ],
     "scripts": [
       {
         "name": "checkdeps",
@@ -1027,10 +1033,6 @@
         "script": "telemetry_unittests.py"
       },
       {
-        "name": "telemetry_gpu_unittests",
-        "script": "telemetry_gpu_unittests.py"
-      },
-      {
         "name": "telemetry_perf_unittests",
         "script": "telemetry_perf_unittests.py"
       },
@@ -1373,16 +1375,18 @@
         "test": "wm_unittests"
       }
     ],
+    "isolated_scripts": [
+      {
+        "isolate_name": "telemetry_gpu_unittests",
+        "name": "telemetry_gpu_unittests"
+      }
+    ],
     "scripts": [
       {
         "name": "telemetry_unittests",
         "script": "telemetry_unittests.py"
       },
       {
-        "name": "telemetry_gpu_unittests",
-        "script": "telemetry_gpu_unittests.py"
-      },
-      {
         "name": "telemetry_perf_unittests",
         "script": "telemetry_perf_unittests.py"
       },