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