rebaseline_server: apply ignored-tests.txt within rebaseline_server, not just on the bots

gm/rebaseline_server/testdata/outputs/expected/compare_configs_test.CompareConfigsTest.test_gm/gm.json

 {
   "extraColumnHeaders": {
     "builder": {
       "headerText": "builder", 
       "isFilterable": true, 
       "isSortable": true, 
       "valuesAndCounts": [
         [
           "Test-Android-GalaxyNexus-SGX540-Arm7-Release", 
           7
         ], 
         [
           "Test-Builder-We-Have-No-Expectations-File-For", 
           3
         ], 
         [
           "Test-Mac10.7-MacMini4.1-GeForce320M-x86_64-Debug", 
-          3
+          4
         ]
       ]
     }, 
     "config": {
       "headerText": "config", 
       "isFilterable": true, 
       "isSortable": true, 
       "valuesAndCounts": [
         [
           "TODO", 
-          13
+          14
         ]
       ]
     }, 
     "resultType": {
       "headerText": "resultType", 
       "isFilterable": true, 
       "isSortable": true, 
       "valuesAndCounts": [
         [
           "failed", 
           4
         ], 
         [
           "no-comparison", 
-          7
+          8
         ], 
         [
           "succeeded", 
           2
         ]
       ]
     }, 
     "test": {
       "headerText": "test", 
       "isFilterable": true, 
       "isSortable": true, 
       "valuesAndCounts": [
         [
           "3x3bitmaprect", 
           3
         ], 
         [
           "aaclip", 
           1
         ], 
         [
           "bigblurs", 
           3
         ], 
         [
           "bitmapsource", 
           1
         ], 
         [
+          "blanket-ignored", 
+          1
+        ], 
+        [
           "displacement", 
           2
         ], 
         [
           "filterbitmap_checkerboard_192_192", 
           1
         ], 
         [
           "filterbitmap_checkerboard_32_2", 
           1
         ], 
         [
           "texdata", 
           1
         ]
       ]
     }
   }, 
   "header": {
-    "dataHash": "-7043844904261310530", 
+    "dataHash": "-3232866296817265056", 
     "isEditable": false, 
     "isExported": true, 
     "schemaVersion": 3, 
     "timeNextUpdateAvailable": null, 
     "timeUpdated": 12345678, 
     "type": "all"
   }, 
   "imagePairs": [
     {
       "extraColumns": {
@@ skipping 121 matching lines @@
         "builder": "Test-Builder-We-Have-No-Expectations-File-For", 
         "config": "TODO", 
         "resultType": "succeeded", 
         "test": "3x3bitmaprect"
       }, 
       "imageAUrl": "bitmap-64bitMD5/3x3bitmaprect/2054956815327187963.png", 
       "imageBUrl": "bitmap-64bitMD5/3x3bitmaprect/2054956815327187963.png", 
       "isDifferent": false
     }, 
     {
+      "extraColumns": {
+        "builder": "Test-Mac10.7-MacMini4.1-GeForce320M-x86_64-Debug", 
+        "config": "TODO", 
+        "resultType": "no-comparison", 
+        "test": "blanket-ignored"
+      }, 
+      "imageAUrl": "bitmap-64bitMD5/blanket-ignored/22222222.png", 
+      "imageBUrl": null, 
+      "isDifferent": true
+    }, 
+    {
       "differenceData": {
         "maxDiffPerChannel": [
           136, 
           68, 
           34
         ], 
         "numDifferingPixels": 6081, 
         "percentDifferingPixels": 2.4324, 
         "perceptualDifference": 1.917199999999994, 
         "weightedDiffMeasure": 0.06644571780084584
@@ skipping 54 matching lines @@
     "imageB": {
       "baseUrl": "http://chromium-skia-gm.commondatastorage.googleapis.com/gm", 
       "description": "gpu"
     }, 
     "whiteDiffs": {
       "baseUrl": "/static/generated-images/whitediffs", 
       "description": "differing pixels in white"
     }
   }
 }