Add blink unit tests to the linux/mac/windows builders.

testing/buildbot/chromium.linux.json

Index: testing/buildbot/chromium.linux.json
diff --git a/testing/buildbot/chromium.linux.json b/testing/buildbot/chromium.linux.json
index d39de428dfbef24317808f6a309b5b488902e01b..e827945d693dce7c7fc6990cdfd225848123e1c0 100644
--- a/testing/buildbot/chromium.linux.json
+++ b/testing/buildbot/chromium.linux.json
@@ -2998,6 +2998,18 @@
       },
       {
         "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "blink_heap_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "blink_platform_unittests"
+      },
+      {
+        "swarming": {
           "can_use_on_swarming_builders": true,
           "shards": 5
         },
@@ -3573,7 +3585,19 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "webkit_unit_tests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "wm_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "wtf_unittests"
       }
     ],
     "isolated_scripts": [