Add swarming support for MB (and the GN bots) in the chromium recipes.

scripts/slave/recipes/chromium.expected/full_tryserver_chromium_perf_linux_perf_tester.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[bisect_tester]/resources/put_temp.py"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "saving url to temp file",
     "stdin": "http://build.chromium.org/p/tryserver.chromium.perf/json/builders/linux_perf_tester/builds/571",
@@ skipping 129 matching lines @@
     "name": "get compile targets for scripts",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
-      "[BUILD]/scripts/slave/cleanup_temp.py"
-    ],
-    "cwd": "[SLAVE_BUILD]",
-    "name": "cleanup_temp"
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
       "\nimport os, sys\nfrom common import chromium_utils\n\nif os.path.exists(sys.argv[1]):\n  chromium_utils.RemoveDirectory(sys.argv[1])\n",
       "[SLAVE_BUILD]/src/out/Release"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "rmtree build directory",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@import os, sys@@@",
       "@@@STEP_LOG_LINE@python.inline@from common import chromium_utils@@@",
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ skipping 14 matching lines @@
       "--factory-properties",
       "{\"bisect_config\": {\"bad_revision\": \"300148\", \"bug_id\": \"425582\", \"builder_host\": \"master4.golo.chromium.org\", \"builder_port\": \"8341\", \"command\": \"tools/perf/run_benchmark -v --browser=release page_cycler.intl_ar_fa_he\", \"good_revision\": \"300138\", \"gs_bucket\": \"chrome-perf\", \"max_time_minutes\": \"5\", \"metric\": \"warm_times/page_load_time\", \"repeat_count\": \"2\", \"test_type\": \"perf\", \"truncate_percent\": \"25\"}, \"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"linux_perf_tester\", \"buildnumber\": 571, \"job_name\": \"f7a7b4135624439cbd27fdd5133d74ec\", \"mastername\": \"tryserver.chromium.perf\", \"parent_build_archive_url\": \"gs://test-domain/test-archive.zip\", \"parent_buildername\": \"Linux Builder\", \"parent_got_revision\": \"1111111\", \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
       "--build-properties",
       "{\"bisect_config\": {\"bad_revision\": \"300148\", \"bug_id\": \"425582\", \"builder_host\": \"master4.golo.chromium.org\", \"builder_port\": \"8341\", \"command\": \"tools/perf/run_benchmark -v --browser=release page_cycler.intl_ar_fa_he\", \"good_revision\": \"300138\", \"gs_bucket\": \"chrome-perf\", \"max_time_minutes\": \"5\", \"metric\": \"warm_times/page_load_time\", \"repeat_count\": \"2\", \"test_type\": \"perf\", \"truncate_percent\": \"25\"}, \"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"linux_perf_tester\", \"buildnumber\": 571, \"job_name\": \"f7a7b4135624439cbd27fdd5133d74ec\", \"mastername\": \"tryserver.chromium.perf\", \"parent_build_archive_url\": \"gs://test-domain/test-archive.zip\", \"parent_buildername\": \"Linux Builder\", \"parent_got_revision\": \"1111111\", \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "extract build"
   },
   {
     "cmd": [
+      "python",
+      "-u",
+      "[BUILD]/scripts/slave/cleanup_temp.py"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "cleanup_temp"
+  },
+  {
+    "cmd": [
       "xvfb-run",
       "-a",
       "tools/perf/run_benchmark",
       "-v",
       "--browser=release",
       "page_cycler.intl_ar_fa_he"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "Performance Test 1/2",
     "stderr": "/path/to/tmp/",
@@ skipping 38 matching lines @@
       "/tmp/dummy2",
       "gs://chrome-perf/bisect-results/f7a7b4135624439cbd27fdd5133d74ec.results"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "gsutil upload",
     "~followup_annotations": [
       "@@@STEP_LINK@gsutil.upload@https://storage.cloud.google.com/chrome-perf/bisect-results/f7a7b4135624439cbd27fdd5133d74ec.results@@@"
     ]
   }
 ]