Mark ui_base_unittests target to be used on Swarming.

testing/buildbot/chromium.win.json

Index: testing/buildbot/chromium.win.json
diff --git a/testing/buildbot/chromium.win.json b/testing/buildbot/chromium.win.json
index 582f21c8fcfc6f423275505d0768976a98b0a3ff..33bdc0fc140c77983ba8a6be3d46eba431b9d3b5 100644
--- a/testing/buildbot/chromium.win.json
+++ b/testing/buildbot/chromium.win.json
@@ -190,6 +190,9 @@
         "test": "sync_unit_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ui_base_unittests"
       },
       {
@@ -440,6 +443,9 @@
         "test": "sync_unit_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ui_base_unittests"
       },
       {
@@ -694,6 +700,9 @@
         "test": "sync_unit_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ui_base_unittests"
       },
       {
@@ -923,6 +932,9 @@
         "test": "sync_unit_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ui_base_unittests"
       },
       {
@@ -1165,6 +1177,9 @@
         "test": "sync_unit_tests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ui_base_unittests"
       },
       {