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

scripts/slave/recipe_modules/chromium/api.py

Index: scripts/slave/recipe_modules/chromium/api.py
diff --git a/scripts/slave/recipe_modules/chromium/api.py b/scripts/slave/recipe_modules/chromium/api.py
index e2dd85330c9271baf4da27a7f4aa41ff43a9c880..fa94a7ea657a0040b2c677b7e4e9c6ee2d56541f 100644
--- a/scripts/slave/recipe_modules/chromium/api.py
+++ b/scripts/slave/recipe_modules/chromium/api.py
@@ -515,12 +515,6 @@ class ChromiumApi(recipe_api.RecipeApi):
       kwargs['wrapper'] = self.get_cros_chrome_sdk_wrapper(clean=True)
     self.m.gclient.runhooks(**kwargs)
 
-  def run_gyp_chromium(self):
-    gyp_chromium_path = self.m.path['checkout'].join('build', 'gyp_chromium.py')
-    env = self.get_env()
-    env.update(self.c.gyp_env.as_jsonish())
-    self.m.python(name='gyp_chromium', script=gyp_chromium_path, env=env);
-
   def run_gn(self, use_goma=False, gn_path=None, build_dir=None, **kwargs):
     if not gn_path:
       gn_path = self.m.path['depot_tools'].join('gn.py')
@@ -577,7 +571,8 @@ class ChromiumApi(recipe_api.RecipeApi):
   def run_mb(self, mastername, buildername, use_goma=True,
              mb_config_path=None, isolated_targets=None, name=None,
              build_dir=None, android_version_code=None,
-             android_version_name=None, gyp_script=None, **kwargs):
+             android_version_name=None, gyp_script=None, phase=None,
+             **kwargs):
     mb_config_path = (mb_config_path or
                       self.m.path['checkout'].join('tools', 'mb',
                                                    'mb_config.pyl'))
@@ -596,6 +591,9 @@ class ChromiumApi(recipe_api.RecipeApi):
         '--config-file', mb_config_path,
     ]
 
+    if phase is not None:
+      args += [ '--phase', str(phase) ]
+
     if use_goma:
       goma_dir = self.c.compile_py.goma_dir
       if not goma_dir: