Enable isolate on Linux release builder.

scripts/slave/recipes/chromium.expected/dynamic_gtest.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
       "chromium.linux",
       "--builder",
       "Linux Tests",
@@ skipping 44 matching lines @@
       "@@@SET_BUILD_PROPERTY@got_v8_revision_git@\"801ada225ddc271c132c3a35f03975671d43e399\"@@@",
       "@@@SET_BUILD_PROPERTY@got_webrtc_revision_git@\"0f90628433546e61d9268596da93418c623137f4\"@@@",
       "@@@SET_BUILD_PROPERTY@got_swarming_client_revision_git@\"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\"@@@",
       "@@@SET_BUILD_PROPERTY@got_revision_git@\"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
+      "[SLAVE_BUILD]/src/tools/swarming_client/swarming.py",
+      "--version"
+    ],
+    "name": "swarming.py --version",
+    "stdout": "/path/to/tmp/",
+    "~followup_annotations": [
+      "@@@STEP_TEXT@0.4.10@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
     "env": {
-      "GYP_DEFINES": "component=static_library gomadir='[BUILD]/goma' target_arch=x64 use_goma=1"
+      "GYP_DEFINES": "component=static_library gomadir='[BUILD]/goma' target_arch=x64 test_isolation_mode=archive test_isolation_outdir=https://isolateserver.appspot.com use_goma=1"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
       "[SLAVE_BUILD]/src/testing/buildbot/chromium.linux.json",
       "/path/to/tmp/json"
@@ skipping 206 matching lines @@
       "--metadata",
       "blink_revision=124383",
       "--metadata",
       "build_number=571",
       "--write-full-results-to",
       "/path/to/tmp/json"
     ],
     "name": "telemetry_perf_unittests"
   }
 ]