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 3f7e0f26f6f7d24d51a90824d84071e0502b91e1..028e98d4cd1bd4b327d31730b8a7f18dd9b3c784 100644
--- a/testing/buildbot/chromium.linux.json
+++ b/testing/buildbot/chromium.linux.json
@@ -972,6 +972,12 @@
         "test": "wm_unittests"
       }
     ],
+    "isolated_scripts": [
+      {
+        "isolate_name": "telemetry_gpu_unittests",
+        "name": "telemetry_gpu_unittests"
+      }
+    ],
     "scripts": [
       {
         "name": "checkdeps",
@@ -990,10 +996,6 @@
         "script": "telemetry_unittests.py"
       },
       {
-        "name": "telemetry_gpu_unittests",
-        "script": "telemetry_gpu_unittests.py"
-      },
-      {
         "name": "telemetry_perf_unittests",
         "script": "telemetry_perf_unittests.py"
       },
@@ -1323,16 +1325,18 @@
         "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"
       },