rebaseline.py self-tests: prepare to add tests of JSON-format rebaselining

tools/tests/rebaseline/output/using-json1-expectations/output-expected/gm-expectations/base-shuttle-win7-intel-float/expected-results.json

Index: tools/tests/rebaseline/output/using-json1-expectations/output-expected/gm-expectations/base-shuttle-win7-intel-float/expected-results.json
===================================================================
--- tools/tests/rebaseline/output/using-json1-expectations/output-expected/gm-expectations/base-shuttle-win7-intel-float/expected-results.json	(revision 0)
+++ tools/tests/rebaseline/output/using-json1-expectations/output-expected/gm-expectations/base-shuttle-win7-intel-float/expected-results.json	(revision 0)
@@ -0,0 +1,52 @@
+{
+   "expected-results" : {
+      "3x3bitmaprect_565.png" : {
+         "allowed-digests" : null,
+         "ignore-failure" : false
+      },
+      "3x3bitmaprect_8888.png" : {
+         "allowed-digests" : null,
+         "ignore-failure" : false
+      },
+      "aaclip_gpu.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 11899819492385205974 ]
+         ],
+         "ignore-failure" : false
+      },
+      "aarectmodes_565.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 14760033689012826769 ]
+         ],
+         "ignore-failure" : false
+      },
+      "imageblur_565.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 3359963596899141322 ]
+         ],
+         "ignore-failure" : false
+      },
+      "imageblur_8888.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 4217923806027861152 ]
+         ],
+         "ignore-failure" : false
+      },
+      "shadertext3_8888.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 3713708307125704716 ]
+         ],
+         "ignore-failure" : false
+      },
+      "xfermodeimagefilter_pdf.png" : {
+         "allowed-digests" : null,
+         "ignore-failure" : false
+      },
+      "xfermodes_pdf.png" : {
+         "allowed-digests" : [
+            [ "bitmap-64bitMD5", 9151974350149210736 ]
+         ],
+         "ignore-failure" : false
+      }
+   }
+}