V8 Buildbot: Switch ignition tests to v8-side test set.

scripts/slave/recipes/v8.expected/full_client_v8_V8_Arm.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "[BUILD]/scripts/slave/git_setup.py",
       "--path",
       "[SLAVE_BUILD]/swarming.client",
       "--url",
       "https://chromium.googlesource.com/external/swarming.client.git"
@@ skipping 454 matching lines @@
       "trigger",
       "--swarming",
       "https://chromium-swarm.appspot.com",
       "--isolate-server",
       "https://isolateserver.appspot.com",
       "--priority",
       "25",
       "--shards",
       "1",
       "--task-name",
-      "Mjsunit - ignition/Ubuntu-14.04/[dummy has/V8 Arm/571",
+      "Ignition/Ubuntu-14.04/[dummy has/V8 Arm/571",
       "--dump-json",
       "/path/to/tmp/json",
       "--expiration",
       "14400",
       "--io-timeout",
       "1200",
       "--hard-timeout",
       "3600",
       "--dimension",
       "cpu",
       "armv7l",
       "--dimension",
       "gpu",
       "none",
       "--dimension",
       "os",
       "Ubuntu-14.04",
       "--dimension",
       "pool",
       "Chrome",
       "--tag",
       "buildername:V8 Arm",
       "--tag",
       "buildnumber:571",
       "--tag",
-      "data:[dummy hash for mjsunit]",
+      "data:[dummy hash for ignition]",
       "--tag",
       "master:client.v8",
       "--tag",
-      "name:Mjsunit - ignition",
+      "name:Ignition",
       "--tag",
       "os:Ubuntu-14.04",
       "--tag",
       "project:v8",
       "--tag",
       "purpose:CI",
       "--tag",
       "purpose:post-commit",
       "--tag",
       "slavename:TestSlavename",
       "--tag",
-      "stepname:Mjsunit - ignition on Ubuntu-14.04",
-      "[dummy hash for mjsunit]",
+      "stepname:Ignition on Ubuntu-14.04",
+      "[dummy hash for ignition]",
       "--",
       "--progress=verbose",
       "--mode",
       "Release",
       "--arch",
       "arm",
       "--outdir",
       "out",
       "--buildbot",
       "--timeout=200",
-      "mjsunit",
+      "ignition",
       "--variants=ignition",
       "--ignition",
       "--exhaustive-variants",
       "--rerun-failures-count=2",
       "--swarming",
       "--json-test-results",
       "${ISOLATED_OUTDIR}/output.json"
     ],
     "cwd": "[SLAVE_BUILD]",
-    "name": "[trigger] Mjsunit - ignition on Ubuntu-14.04",
+    "name": "[trigger] Ignition on Ubuntu-14.04",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"Mjsunit - ignition/Ubuntu-14.04/[dummy has/V8 Arm/571\", @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"Ignition/Ubuntu-14.04/[dummy has/V8 Arm/571\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tasks\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"Mjsunit - ignition/Ubuntu-14.04/[dummy has/V8 Arm/571\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"Ignition/Ubuntu-14.04/[dummy has/V8 Arm/571\": {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"shard_index\": 0, @@@",
       "@@@STEP_LOG_LINE@json.output@      \"task_id\": \"10000\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"view_url\": \"https://chromium-swarm.appspot.com/user/task/10000\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  }@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
       "@@@STEP_LINK@shard #0@https://chromium-swarm.appspot.com/user/task/10000@@@"
     ]
   },
@@ skipping 277 matching lines @@
       "--merged-test-output",
       "/path/to/tmp/json",
       "--",
       "collect",
       "--swarming",
       "https://chromium-swarm.appspot.com",
       "--decorate",
       "--print-status-updates",
       "--shards",
       "1",
-      "Mjsunit - ignition/Ubuntu-14.04/[dummy has/V8 Arm/571",
+      "Ignition/Ubuntu-14.04/[dummy has/V8 Arm/571",
       "--timeout",
       "18000"
     ],
     "cwd": "[SLAVE_BUILD]",
-    "name": "Mjsunit - ignition",
+    "name": "Ignition",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@durations@01:01:002 mjsunit/Cool.Test@@@",
       "@@@STEP_LOG_LINE@durations@00:00:101 mjsunit/Cool.Test2@@@",
       "@@@STEP_LOG_LINE@durations@@@@",
       "@@@STEP_LOG_LINE@durations@Details:@@@",
       "@@@STEP_LOG_LINE@durations@@@@",
       "@@@STEP_LOG_LINE@durations@Test: mjsunit/Cool.Test@@@",
       "@@@STEP_LOG_LINE@durations@Flags: -f@@@",
       "@@@STEP_LOG_LINE@durations@Command: d8 -f mjsunit/Cool.Test@@@",
       "@@@STEP_LOG_LINE@durations@Duration: 01:01:002@@@",
@@ skipping 46 matching lines @@
       "@@@STEP_LOG_LINE@durations@Duration: 00:00:101@@@",
       "@@@STEP_LOG_END@durations@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]