make compare_rendered_pictures process render_pictures's new JSON output format

gm/rebaseline_server/testdata/inputs/render_pictures_output/after_patch/builder1/output.json

Index: gm/rebaseline_server/testdata/inputs/render_pictures_output/after_patch/builder1/output.json
diff --git a/gm/rebaseline_server/testdata/inputs/render_pictures_output/after_patch/builder1/output.json b/gm/rebaseline_server/testdata/inputs/render_pictures_output/after_patch/builder1/output.json
index 6b9acc04504c4feda46fd952cd426e9d55a29cbb..9bd6607da3ad12fdeb4e70c6c2e7bf4a5ec28710 100644
--- a/gm/rebaseline_server/testdata/inputs/render_pictures_output/after_patch/builder1/output.json
+++ b/gm/rebaseline_server/testdata/inputs/render_pictures_output/after_patch/builder1/output.json
@@ -1,8 +1,24 @@
 {
+   "header" : {

[epoger, 2014/05/02 21:24:52]

Updated render_pictures JSON summary format to reflect
https://github.com/google/skia/commit/24c568c1597de9f54df8cea3b46f2e93028a5aec

+      "type" : "ChecksummedImages",

[epoger, 2014/05/02 21:24:52]

In a future CL, I will make the unittest call render_pictures to generate test
input files, rather than using canned input files.  That way, any changes in
render_pictures will be instantly reflected in these unittest results.

+      "revision" : 1
+   },
    "actual-results" : {
-      "no-comparison" : {
-         "changed.png" : [ "bitmap-64bitMD5", 2520753504544298264 ],
-         "unchanged.png" : [ "bitmap-64bitMD5", 11092453015575919668 ]
+      "changed.skp" : {
+         "whole-image" : {
+           "checksumAlgorithm" : "bitmap-64bitMD5",
+           "checksumValue" : 2520753504544298264,
+           "comparisonResult" : "no-comparison",
+           "filepath" : "bitmap-64bitMD5_2520753504544298264.png"
+         }
+      },
+      "unchanged.skp" : {
+         "whole-image" : {
+           "checksumAlgorithm" : "bitmap-64bitMD5",
+           "checksumValue" : 11092453015575919668,
+           "comparisonResult" : "no-comparison",
+           "filepath" : "bitmap-64bitMD5_11092453015575919668.png"
+         }
       }
    }
 }