Add initial baselines for discard GM

Review URL: https://codereview.chromium.org/267763003

git-svn-id: http://skia.googlecode.com/svn/trunk@14528 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/expectations/gm/Test-Win8-ShuttleA-HD7770-x86-Release/expected-results.json b/expectations/gm/Test-Win8-ShuttleA-HD7770-x86-Release/expected-results.json
index 3f7ea88..7bc5b20 100644
--- a/expectations/gm/Test-Win8-ShuttleA-HD7770-x86-Release/expected-results.json
+++ b/expectations/gm/Test-Win8-ShuttleA-HD7770-x86-Release/expected-results.json
@@ -4842,6 +4842,15 @@
       ], 
       "reviewed-by-human": false
     }, 
+    "discard_gpu.png": {
+      "allowed-digests": [
+        [
+          "bitmap-64bitMD5", 
+          11635187478196931850
+        ]
+      ], 
+      "reviewed-by-human": true
+    }, 
     "displacement_565.png": {
       "allowed-digests": [
         [