Remove use of "use_mirror" recipe property.

scripts/slave/recipe_modules/perf_dashboard/example.expected/linux_use_mirror.json

Index: scripts/slave/recipe_modules/perf_dashboard/example.expected/linux_use_mirror.json
diff --git a/scripts/slave/recipe_modules/perf_dashboard/example.expected/linux_use_mirror.json b/scripts/slave/recipe_modules/perf_dashboard/example.expected/linux_use_mirror.json
deleted file mode 100644
index c629b632871a6f67837c72cc43f4b19138c17c2f..0000000000000000000000000000000000000000
--- a/scripts/slave/recipe_modules/perf_dashboard/example.expected/linux_use_mirror.json
+++ /dev/null
@@ -1,40 +0,0 @@
-[
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[build::perf_dashboard]/resources/post_json.py"
-    ],
-    "name": "perf dashboard post",
-    "stdin": "{\"data\": [{\"bot\": \"multivm-windows-perf-be\", \"buildername\": \"multivm-windows-perf-be\", \"buildnumber\": 75, \"error\": \"0.5\", \"master\": \"client.dart.fyi\", \"masterid\": \"client.dart.fyi\", \"revision\": 33241, \"supplemental_columns\": {\"r_webkit_rev\": \"167808\"}, \"test\": \"sunspider/string-unpack-code/ref\", \"units\": \"ms\", \"value\": \"18.5\"}, {\"bot\": \"multivm-windows-perf-be\", \"buildername\": \"multivm-windows-perf-be\", \"buildnumber\": 75, \"error\": \"0.4898\", \"master\": \"client.dart.fyi\", \"masterid\": \"client.dart.fyi\", \"revision\": 33241, \"supplemental_columns\": {\"r_webkit_rev\": \"167808\"}, \"test\": \"sunspider/string-unpack-code\", \"units\": \"ms\", \"value\": \"18.4\"}], \"url\": \"https://chromeperf.appspot.com/add_point\"}",
-    "~followup_annotations": [
-      "@@@STEP_LINK@Results Dashboard@https://chromeperf.appspot.com/report?rev=33241&masters=client.dart.fyi&tests=sunspider%2Fstring-unpack-code&bots=bot_name@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[build::perf_dashboard]/resources/post_json.py"
-    ],
-    "name": "Post bisect results",
-    "stdin": "{\"data\": {\"status\": \"completed\", \"try_job_id\": 1}, \"url\": \"https://chromeperf.appspot.com/post_bisect_results\"}",
-    "stdout": "/path/to/tmp/json",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"post_data\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"status\": \"completed\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"try_job_id\": 1@@@",
-      "@@@STEP_LOG_LINE@json.output@  }, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"status_code\": 200, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"text\": \"\"@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
-    "name": "$result",
-    "recipe_result": null,
-    "status_code": 0
-  }
-]