Run native_theme unittests everywhere we run views_unittests.

testing/buildbot/chromium.mac.json

Index: testing/buildbot/chromium.mac.json
diff --git a/testing/buildbot/chromium.mac.json b/testing/buildbot/chromium.mac.json
index 77cf073988116803f5b1b242a83ab7bc7b3f63d1..72133986d4833cad0abad91093f6131695d64d27 100644
--- a/testing/buildbot/chromium.mac.json
+++ b/testing/buildbot/chromium.mac.json
@@ -254,6 +254,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "native_theme_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "net_unittests"
       },
       {
@@ -599,6 +605,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "native_theme_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "net_unittests"
       },
       {
@@ -945,6 +957,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "native_theme_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "net_unittests"
       },
       {
@@ -1279,6 +1297,12 @@
         "swarming": {
           "can_use_on_swarming_builders": true
         },
+        "test": "native_theme_unittests"
+      },
+      {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "net_unittests"
       },
       {