Disable swiftshader_unittests on some non-swarming GPU FYI mac bots

content/test/gpu/generate_buildbot_json.py

Index: content/test/gpu/generate_buildbot_json.py
diff --git a/content/test/gpu/generate_buildbot_json.py b/content/test/gpu/generate_buildbot_json.py
index 88fc66ee731830a6a7d6909ab839b1d84bcfec31..253c09df79ce79d6400067425d297ca373607802 100755
--- a/content/test/gpu/generate_buildbot_json.py
+++ b/content/test/gpu/generate_buildbot_json.py
@@ -1447,6 +1447,9 @@ COMMON_GTESTS = {
       {
         'names': [
           'Linux ChromiumOS Ozone (Intel)',
+          'Mac Experimental Retina Release (AMD)',
+          'Mac Experimental Retina Release (NVIDIA)',
+          'Mac Pro Release (AMD)',
         ],
       },
     ],