Add pdf-native textblobshader GM baseline

expectations/gm/Test-Mac10.8-MacMini4.1-GeForce320M-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 16735 matching lines @@
     }, 
     "textblob_pdf-native.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           7693679797078782821
         ]
       ], 
       "reviewed-by-human": true
     }, 
+    "textblobshader_pdf-native.png": {
+      "allowed-digests": [
+        [
+          "bitmap-64bitMD5", 
+          8689938548045974643
+        ]
+      ], 
+      "bugs": [
+        2983
+      ], 
+      "reviewed-by-human": true
+    }, 
     "texteffects_565.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           11038407228975641784
         ]
       ], 
       "bugs": [
         1578
       ], 
@@ skipping 1469 matching lines @@
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           10030599291822810250
         ]
       ], 
       "reviewed-by-human": false
     }
   }
 }