Update from https://crrev.com/308331

testing/buildbot/chromium_trybot.json

Index: testing/buildbot/chromium_trybot.json
diff --git a/testing/buildbot/chromium_trybot.json b/testing/buildbot/chromium_trybot.json
index 9a0e4af707a739848893e603ede83b9e0fca844e..7925d5df7ba7a800ce062da134715492163d0c94 100644
--- a/testing/buildbot/chromium_trybot.json
+++ b/testing/buildbot/chromium_trybot.json
@@ -3,12 +3,22 @@
     "all"
   ],
   "gtest_tests": [
-    "accessibility_unittests",
+    {
+      "test": "accessibility_unittests",
+      "swarming": {
+        "can_use_on_swarming_builders": true
+      }
+    },
     {
       "test": "app_installer_unittests",
       "platforms": ["win"]
     },
-    "app_list_unittests",
+    {
+      "test": "app_list_unittests",
+      "swarming": {
+        "can_use_on_swarming_builders": true
+      }
+    },
     {
       "test": "ash_unittests",
       "chromium_configs": [
@@ -84,13 +94,23 @@
       "platforms": ["linux"]
     },
     "device_unittests",
-    "events_unittests",
+    {
+      "test": "events_unittests",
+      "swarming": {
+        "can_use_on_swarming_builders": true
+      }
+    },
     {
       "test": "extensions_unittests",
       "platforms": ["win", "mac", "linux"]
     },
     "gcm_unit_tests",
-    "gfx_unittests",
+    {
+      "test": "gfx_unittests",
+      "swarming": {
+        "can_use_on_swarming_builders": true
+      }
+    },
     "google_apis_unittests",
     "gpu_unittests",
     {
@@ -116,7 +136,12 @@
     },
     "media_perftests",
     "media_unittests",
-    "message_center_unittests",
+    {
+      "test": "message_center_unittests",
+      "swarming": {
+        "can_use_on_swarming_builders": true
+      }
+    },
     "mojo_common_unittests",
     "mojo_public_bindings_unittests",
     "mojo_public_environment_unittests",
@@ -157,7 +182,12 @@
       }
     },
     "sync_unit_tests",
-    "ui_base_unittests",
+    {
+      "test": "ui_base_unittests",
+      "swarming": {
+        "can_use_on_swarming_builders": true
+      }
+    },
     "ui_touch_selection_unittests",
     {
       "test": "unit_tests",