Switch the "Linux ChromiumOS Builder" to MB

scripts/slave/recipes/chromium_trybot.expected/recipe_config_changes_not_retried_without_patch.json

Index: scripts/slave/recipes/chromium_trybot.expected/recipe_config_changes_not_retried_without_patch.json
diff --git a/scripts/slave/recipes/chromium_trybot.expected/recipe_config_changes_not_retried_without_patch.json b/scripts/slave/recipes/chromium_trybot.expected/recipe_config_changes_not_retried_without_patch.json
index 5209d60bef121385d0afff4b951d4b2f24e34094..19f12993b5e45e6d1106ef106a48d37d1fb84620 100644
--- a/scripts/slave/recipes/chromium_trybot.expected/recipe_config_changes_not_retried_without_patch.json
+++ b/scripts/slave/recipes/chromium_trybot.expected/recipe_config_changes_not_retried_without_patch.json
@@ -138,6 +138,7 @@
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
+      "GYP_CHROMIUM_NO_ACTION": "1",
       "GYP_DEFINES": "chromeos=1 component=static_library dcheck_always_on=1 fastbuild=1 ffmpeg_branding=ChromeOS gomadir='[SLAVE_BUILD]/src/build/goma/client' proprietary_codecs=1 target_arch=x64 test_isolation_mode=prepare use_goma=1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
@@ -279,6 +280,25 @@
     "cmd": [
       "python",
       "-u",
+      "[SLAVE_BUILD]/src/tools/mb/mb.py",
+      "gen",
+      "-m",
+      "tryserver.chromium.linux",
+      "-b",
+      "linux_chromium_chromeos_rel_ng",
+      "--config-file",
+      "[SLAVE_BUILD]/src/tools/mb/mb_config.pyl",
+      "--goma-dir",
+      "[SLAVE_BUILD]/src/build/goma/client",
+      "//out/Release"
+    ],
+    "cwd": "[SLAVE_BUILD]",
+    "name": "generate_build_files (with patch)"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "RECIPE_PACKAGE_REPO[build]/scripts/tools/runit.py",
       "--show-path",
       "python",