V8: Let peek-gn use mb to reuse v8-side configs.

scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___internal_snapshot_test_failures.json

Index: scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___internal_snapshot_test_failures.json
diff --git a/scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___internal_snapshot_test_failures.json b/scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___internal_snapshot_test_failures.json
index 550eeaa8ea7d6d2407286930ab0e39625c583b73..628e3b89f23b99e7c71249df1926b5ccbcd44cf2 100644
--- a/scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___internal_snapshot_test_failures.json
+++ b/scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux64___internal_snapshot_test_failures.json
@@ -162,13 +162,32 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gn.py",
-      "--root=[SLAVE_BUILD]/v8",
+      "RECIPE_MODULE[build::v8]/resources/patch_mb_config.py",
+      "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
+      "/path/to/tmp/"
+    ],
+    "name": "patch mb config (fyi)"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "[SLAVE_BUILD]/v8/tools/mb/mb.py",
       "gen",
-      "[TMP_BASE]/v8_gn_tmp_1",
-      "--args=is_debug=false target_cpu=\"x64\" use_goma=true goma_dir=\"[CACHE]/cipd/goma\""
+      "-m",
+      "client.v8",
+      "-b",
+      "V8 Linux64 - internal snapshot",
+      "--config-file",
+      "[mb config]",
+      "--goma-dir",
+      "[CACHE]/cipd/goma",
+      "[TMP_BASE]/v8_gn_tmp_1"
     ],
-    "name": "gn"
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
+    "name": "generate_build_files with gn (fyi)"
   },
   {
     "cmd": [
@@ -1144,13 +1163,35 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gn.py",
-      "--root=[SLAVE_BUILD]/v8",
+      "RECIPE_MODULE[build::v8]/resources/patch_mb_config.py",
+      "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
+      "/path/to/tmp/"
+    ],
+    "name": "Bisect a0.patch mb config (fyi)",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "[SLAVE_BUILD]/v8/tools/mb/mb.py",
       "gen",
-      "[TMP_BASE]/v8_gn_tmp_2",
-      "--args=is_debug=false target_cpu=\"x64\" use_goma=true goma_dir=\"[CACHE]/cipd/goma\""
+      "-m",
+      "client.v8",
+      "-b",
+      "V8 Linux64 - internal snapshot",
+      "--config-file",
+      "[mb config]",
+      "--goma-dir",
+      "[CACHE]/cipd/goma",
+      "[TMP_BASE]/v8_gn_tmp_2"
     ],
-    "name": "Bisect a0.gn",
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
+    "name": "Bisect a0.generate_build_files with gn (fyi)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
@@ -1565,13 +1606,35 @@
     "cmd": [
       "python",
       "-u",
-      "[DEPOT_TOOLS]/gn.py",
-      "--root=[SLAVE_BUILD]/v8",
+      "RECIPE_MODULE[build::v8]/resources/patch_mb_config.py",
+      "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
+      "/path/to/tmp/"
+    ],
+    "name": "Bisect a2.patch mb config (fyi)",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
+      "[SLAVE_BUILD]/v8/tools/mb/mb.py",
       "gen",
-      "[TMP_BASE]/v8_gn_tmp_3",
-      "--args=is_debug=false target_cpu=\"x64\" use_goma=true goma_dir=\"[CACHE]/cipd/goma\""
+      "-m",
+      "client.v8",
+      "-b",
+      "V8 Linux64 - internal snapshot",
+      "--config-file",
+      "[mb config]",
+      "--goma-dir",
+      "[CACHE]/cipd/goma",
+      "[TMP_BASE]/v8_gn_tmp_3"
     ],
-    "name": "Bisect a2.gn",
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
+    "name": "Bisect a2.generate_build_files with gn (fyi)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]