Add the perceptual difference metric to the rebaseline server

gm/rebaseline_server/tests/outputs/expected/results_test.ResultsTest.test_gm/gm.json

Index: gm/rebaseline_server/tests/outputs/expected/results_test.ResultsTest.test_gm/gm.json
diff --git a/gm/rebaseline_server/tests/outputs/expected/results_test.ResultsTest.test_gm/gm.json b/gm/rebaseline_server/tests/outputs/expected/results_test.ResultsTest.test_gm/gm.json
index 89ad21b2411366d6ea1a7fbed55639ebcf414edf..9aef669384fba8cbc736ab2b8cd6749774e719d9 100644
--- a/gm/rebaseline_server/tests/outputs/expected/results_test.ResultsTest.test_gm/gm.json
+++ b/gm/rebaseline_server/tests/outputs/expected/results_test.ResultsTest.test_gm/gm.json
@@ -53,6 +53,7 @@
       ], 
       "numDifferingPixels": 120000, 
       "percentDifferingPixels": 75.0, 
+      "perceptualDifference": 50.122499999999995, 
       "resultType": "failed", 
       "reviewed-by-human": null, 
       "test": "texdata", 
@@ -76,6 +77,7 @@
       ], 
       "numDifferingPixels": 77691, 
       "percentDifferingPixels": 17.593070652173914, 
+      "perceptualDifference": 100, 
       "resultType": "failure-ignored", 
       "reviewed-by-human": false, 
       "test": "filterbitmap_checkerboard_192_192", 
@@ -99,6 +101,7 @@
       ], 
       "numDifferingPixels": 82952, 
       "percentDifferingPixels": 18.784420289855074, 
+      "perceptualDifference": 100, 
       "resultType": "failure-ignored", 
       "reviewed-by-human": false, 
       "test": "filterbitmap_checkerboard_192_192", 
@@ -122,6 +125,7 @@
       ], 
       "numDifferingPixels": 53150, 
       "percentDifferingPixels": 12.035778985507246, 
+      "perceptualDifference": 100, 
       "resultType": "failure-ignored", 
       "reviewed-by-human": false, 
       "test": "filterbitmap_checkerboard_32_2", 
@@ -145,6 +149,7 @@
       ], 
       "numDifferingPixels": 53773, 
       "percentDifferingPixels": 12.17685688405797, 
+      "perceptualDifference": 100, 
       "resultType": "failure-ignored", 
       "reviewed-by-human": false, 
       "test": "filterbitmap_checkerboard_32_2", 
@@ -208,6 +213,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect", 
@@ -227,6 +233,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect", 
@@ -244,6 +251,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": null, 
       "test": "aaclip", 
@@ -261,6 +269,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": null, 
       "test": "aaclip", 
@@ -278,6 +287,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": null, 
       "test": "displacement", 
@@ -295,6 +305,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": null, 
       "test": "displacement", 
@@ -312,6 +323,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": null, 
       "test": "displacement", 
@@ -329,6 +341,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": null, 
       "test": "displacement", 
@@ -348,6 +361,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "displacement", 
@@ -422,6 +436,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect", 
@@ -441,6 +456,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect", 
@@ -460,6 +476,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect", 
@@ -479,6 +496,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect", 
@@ -498,6 +516,7 @@
       "maxDiffPerChannel": 0, 
       "numDifferingPixels": 0, 
       "percentDifferingPixels": 0, 
+      "perceptualDifference": 0, 
       "resultType": "succeeded", 
       "reviewed-by-human": false, 
       "test": "3x3bitmaprect",