Convert webkit_unit_tests to run exclusively on Swarming

testing/buildbot/chromium.webkit.json

Index: testing/buildbot/chromium.webkit.json
diff --git a/testing/buildbot/chromium.webkit.json b/testing/buildbot/chromium.webkit.json
index 117ddd1ac190d7ffa12c7c1014eda666ddd7ed68..27d75708683dfccda8cd505737bbaa7886714878 100644
--- a/testing/buildbot/chromium.webkit.json
+++ b/testing/buildbot/chromium.webkit.json
@@ -675,6 +675,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -710,6 +713,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -745,6 +751,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -780,6 +789,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -815,6 +827,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -850,6 +865,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -885,6 +903,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -920,6 +941,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -955,6 +979,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -990,6 +1017,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1025,6 +1055,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1060,6 +1093,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1095,6 +1131,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1130,6 +1169,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1165,6 +1207,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1200,6 +1245,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1235,6 +1283,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1270,6 +1321,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1305,6 +1359,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1340,6 +1397,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1375,6 +1435,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1400,6 +1463,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1425,6 +1491,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1460,6 +1529,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1495,6 +1567,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {
@@ -1530,6 +1605,9 @@
         "test": "blink_platform_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "webkit_unit_tests"
       },
       {