rebaseline pictureshader GM on GPU

expectations/gm/Test-Mac10.8-MacMini4.1-GeForce320M-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 12366 matching lines @@
           "bitmap-64bitMD5", 
           18338139396266575549
         ]
       ], 
       "reviewed-by-human": true
     }, 
     "pictureshader_gpu.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          17107820280284794071
+          12439977133390197663
         ]
       ], 
       "reviewed-by-human": true
     }, 
     "pictureshader_pdf-mac.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           11712572171173905369
         ]
@@ skipping 3961 matching lines @@
           7829854837061118142
         ]
       ], 
       "bugs": [
         1578
       ], 
       "reviewed-by-human": false
     }
   }
 }