rebaseline srcmode for gpus -- now pass samplecount

expectations/gm/Test-Win7-ShuttleA-HD2000-x86-Debug/expected-results.json

 {
   "actual-results": {
     "failed": null, 
     "failure-ignored": null, 
     "no-comparison": null, 
     "succeeded": null
   }, 
   "expected-results": {
     "3x3bitmaprect_565.png": {
       "allowed-digests": [
@@ skipping 12499 matching lines @@
           "bitmap-64bitMD5", 
           14019814087375927425
         ]
       ], 
       "bugs": [
         1578
       ], 
       "reviewed-by-human": false
     }
   }
-}
+}