Ignore buggy clip gm on Mac 10.9

expectations/gm/Test-Mac10.9-MacMini6.2-HD4000-x86_64-Release/expected-results.json

 {
   "actual-results": {
     "failed": null, 
     "failure-ignored": null, 
     "no-comparison": null, 
     "succeeded": null
   }, 
   "expected-results": {
     "3x3bitmaprect_565.png": {
       "allowed-digests": [
@@ skipping 16697 matching lines @@
       ], 
       "reviewed-by-human": true
     }, 
     "simpleaaclip_path_gpu.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           14852444518787952875
         ]
       ], 
+      "ignore-failure": true, 
       "reviewed-by-human": true
     }, 
     "simpleaaclip_path_pdf-mac.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           12316334156083509454
         ]
       ], 
       "reviewed-by-human": true
@@ skipping 2608 matching lines @@
     "yuv_to_rgb_effect_gpu.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           12937422788648264516
         ]
       ], 
       "reviewed-by-human": true
     }
   }
-}
+}