Add buggy GPU baselines for MultiPictureDraw Sierpinski GM (with bug label)

expectations/gm/Test-Win8-ShuttleA-HD7770-x86_64-Release/expected-results.json

Index: expectations/gm/Test-Win8-ShuttleA-HD7770-x86_64-Release/expected-results.json
diff --git a/expectations/gm/Test-Win8-ShuttleA-HD7770-x86_64-Release/expected-results.json b/expectations/gm/Test-Win8-ShuttleA-HD7770-x86_64-Release/expected-results.json
index e25e2e004a961d1cf22173fbcd7615df2dafea09..182f4af9df93fc92fb39f5ead475fb6eb0f1540e 100644
--- a/expectations/gm/Test-Win8-ShuttleA-HD7770-x86_64-Release/expected-results.json
+++ b/expectations/gm/Test-Win8-ShuttleA-HD7770-x86_64-Release/expected-results.json
@@ -9795,6 +9795,18 @@
       ], 
       "reviewed-by-human": true
     }, 
+    "multipicturedraw_sierpinski_simple_gpu.png": {
+      "allowed-digests": [
+        [
+          "bitmap-64bitMD5", 
+          10893642616199552496
+        ]
+      ], 
+      "bugs": [
+        2979
+      ], 
+      "reviewed-by-human": true
+    }, 
     "multipicturedraw_sierpinski_tiled_565.png": {
       "allowed-digests": [
         [
@@ -9813,6 +9825,18 @@
       ], 
       "reviewed-by-human": true
     }, 
+    "multipicturedraw_sierpinski_tiled_gpu.png": {
+      "allowed-digests": [
+        [
+          "bitmap-64bitMD5", 
+          553107760339398535
+        ]
+      ], 
+      "bugs": [
+        2979
+      ], 
+      "reviewed-by-human": true
+    }, 
     "nested_aa_565.png": {
       "allowed-digests": [
         [