Add support for "additional_mirrors" property in trybot configs.

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

Index: scripts/slave/recipes/chromium.expected/full_chromium_gpu_GPU_Linux_Builder.json
diff --git a/scripts/slave/recipes/chromium.expected/full_chromium_gpu_fyi_GPU_NextGen_Linux_Builder.json b/scripts/slave/recipes/chromium.expected/full_chromium_gpu_GPU_Linux_Builder.json
similarity index 92%
copy from scripts/slave/recipes/chromium.expected/full_chromium_gpu_fyi_GPU_NextGen_Linux_Builder.json
copy to scripts/slave/recipes/chromium.expected/full_chromium_gpu_GPU_Linux_Builder.json
index 7216d45f9db3beea6e9205981a266b7f8a16341b..ff2acfefac1e303d8b84b0474d440f2040ca319d 100644
--- a/scripts/slave/recipes/chromium.expected/full_chromium_gpu_fyi_GPU_NextGen_Linux_Builder.json
+++ b/scripts/slave/recipes/chromium.expected/full_chromium_gpu_GPU_Linux_Builder.json
@@ -5,9 +5,9 @@
       "-u",
       "[BUILD]/scripts/slave/bot_update.py",
       "--master",
-      "chromium.gpu.fyi",
+      "chromium.gpu",
       "--builder",
-      "GPU NextGen Linux Builder",
+      "GPU Linux Builder",
       "--slave",
       "TestSlavename",
       "--spec",
@@ -121,15 +121,15 @@
       "python",
       "-u",
       "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
-      "[SLAVE_BUILD]/src/testing/buildbot/chromium.gpu.fyi.json",
+      "[SLAVE_BUILD]/src/testing/buildbot/chromium.gpu.json",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "read test spec",
     "~followup_annotations": [
-      "@@@STEP_TEXT@path: [SLAVE_BUILD]/src/testing/buildbot/chromium.gpu.fyi.json@@@",
+      "@@@STEP_TEXT@path: [SLAVE_BUILD]/src/testing/buildbot/chromium.gpu.json@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"Linux NextGen Release (NVIDIA)\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"Linux Release (NVIDIA)\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"gtest_tests\": [@@@",
       "@@@STEP_LOG_LINE@json.output@      {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"swarming\": {@@@",
@@ -157,7 +157,7 @@
       "--paths",
       "{\"build\": \"[BUILD]\", \"checkout\": \"[SLAVE_BUILD]/src\"}",
       "--properties",
-      "{\"buildername\": \"GPU NextGen Linux Builder\", \"buildnumber\": 571, \"mastername\": \"chromium.gpu.fyi\", \"slavename\": \"TestSlavename\", \"target_platform\": \"linux\"}"
+      "{\"buildername\": \"GPU Linux Builder\", \"buildnumber\": 571, \"mastername\": \"chromium.gpu\", \"slavename\": \"TestSlavename\", \"target_platform\": \"linux\"}"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "get compile targets for scripts",
@@ -194,9 +194,9 @@
       "[SLAVE_BUILD]/src/tools/mb/mb.py",
       "gen",
       "-m",
-      "chromium.gpu.fyi",
+      "chromium.gpu",
       "-b",
-      "GPU NextGen Linux Builder",
+      "GPU Linux Builder",
       "--config-file",
       "[SLAVE_BUILD]/src/tools/mb/mb_config.pyl",
       "--goma-dir",
@@ -282,13 +282,13 @@
       "--target",
       "Release",
       "--build-url",
-      "gs://chromium-gpu-fyi-archive/chromium.gpu.fyi/GPU NextGen Linux Builder",
+      "gs://chromium-gpu-fyi-archive/chromium.gpu/GPU Linux Builder",
       "--build_revision",
       "f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9",
       "--factory-properties",
-      "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"GPU NextGen Linux Builder\", \"buildnumber\": 571, \"mastername\": \"chromium.gpu.fyi\", \"parent_buildername\": null, \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
+      "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"GPU Linux Builder\", \"buildnumber\": 571, \"mastername\": \"chromium.gpu\", \"parent_buildername\": null, \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}",
       "--build-properties",
-      "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"GPU NextGen Linux Builder\", \"buildnumber\": 571, \"mastername\": \"chromium.gpu.fyi\", \"parent_buildername\": null, \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}"
+      "{\"blamelist\": [\"cool_dev1337@chromium.org\", \"hax@chromium.org\"], \"buildername\": \"GPU Linux Builder\", \"buildnumber\": 571, \"mastername\": \"chromium.gpu\", \"parent_buildername\": null, \"recipe\": \"chromium\", \"slavename\": \"TestSlavename\", \"workdir\": \"/path/to/workdir/TestSlavename\"}"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "package build"
@@ -299,7 +299,7 @@
     "name": "trigger",
     "trigger_specs": [
       {
-        "builder_name": "Linux NextGen Release (NVIDIA)",
+        "builder_name": "Linux Release (NVIDIA)",
         "properties": {
           "parent_got_angle_revision": "fac9503c46405f77757b9a728eb85b8d7bc6080c",
           "parent_got_angle_revision_cp": "refs/heads/master@{#297276}",
@@ -317,7 +317,7 @@
       }
     ],
     "~followup_annotations": [
-      "@@@STEP_TEXT@Linux NextGen Release (NVIDIA)@@@"
+      "@@@STEP_TEXT@Linux Release (NVIDIA)@@@"
     ]
   },
   {