Reland "Change PGO recipe to use MB now that it supports multiple phases."

scripts/slave/recipes/chromium_pgo.expected/full_tryserver_chromium_win_win_pgo.json

Index: scripts/slave/recipes/chromium_pgo.expected/full_tryserver_chromium_win_win_pgo.json
diff --git a/scripts/slave/recipes/chromium_pgo.expected/full_tryserver_chromium_win_win_pgo.json b/scripts/slave/recipes/chromium_pgo.expected/full_tryserver_chromium_win_win_pgo.json
index 4be43a8c5e80e15a91c845dcecf147258c247f3f..319f88ddea0387dcc30dd02839232e44eb789969 100644
--- a/scripts/slave/recipes/chromium_pgo.expected/full_tryserver_chromium_win_win_pgo.json
+++ b/scripts/slave/recipes/chromium_pgo.expected/full_tryserver_chromium_win_win_pgo.json
@@ -157,15 +157,24 @@
     "cmd": [
       "python",
       "-u",
-      "[SLAVE_BUILD]\\src\\build\\gyp_chromium.py"
+      "[SLAVE_BUILD]\\src\\tools\\mb\\mb.py",
+      "gen",
+      "-m",
+      "tryserver.chromium.win",
+      "-b",
+      "win_pgo",
+      "--config-file",
+      "[SLAVE_BUILD]\\src\\tools\\mb\\mb_config.pyl",
+      "--phase",
+      "1",
+      "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]\\src",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json",
-      "GYP_DEFINES": "buildtype=Official chrome_pgo_phase=1 component=static_library fastbuild=0 target_arch=ia32 use_goma=0",
-      "GYP_MSVS_VERSION": "2015",
-      "PATH": "[SLAVE_BUILD]\\src\\out\\Release;%(PATH)s"
+      "GYP_MSVS_VERSION": "2015"
     },
-    "name": "gyp_chromium"
+    "name": "generate_build_files"
   },
   {
     "cmd": [
@@ -666,14 +675,24 @@
     "cmd": [
       "python",
       "-u",
-      "[SLAVE_BUILD]\\src\\build\\gyp_chromium.py"
+      "[SLAVE_BUILD]\\src\\tools\\mb\\mb.py",
+      "gen",
+      "-m",
+      "tryserver.chromium.win",
+      "-b",
+      "win_pgo",
+      "--config-file",
+      "[SLAVE_BUILD]\\src\\tools\\mb\\mb_config.pyl",
+      "--phase",
+      "2",
+      "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]\\src",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json",
-      "GYP_DEFINES": "buildtype=Official chrome_pgo_phase=2 component=static_library fastbuild=0 target_arch=ia32 use_goma=0",
       "GYP_MSVS_VERSION": "2015"
     },
-    "name": "gyp_chromium (2)"
+    "name": "generate_build_files (2)"
   },
   {
     "cmd": [