De-duplicate steps between chromium and chromium_trybot recipes

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 b4d7f816ec3877215d4d34a8ae59954ecb457a94..4effde63faa7704f70e0234c74d39ad570bcde90 100644
--- a/scripts/slave/recipe_modules/chromium/api.py
+++ b/scripts/slave/recipe_modules/chromium/api.py
@@ -6,6 +6,7 @@ from slave import recipe_api
 from slave import recipe_util
 
 from . import builders
+from . import steps
 
 
 class TestLauncherFilterFileInputPlaceholder(recipe_util.Placeholder):
@@ -53,6 +54,10 @@ class ChromiumApi(recipe_api.RecipeApi):
     return builders.BUILDERS
 
   @property
+  def steps(self):
+    return steps
+
+  @property
   def output_dir(self):
     """Return the path to the built executable directory."""
     return self.c.build_dir.join(self.c.build_config_fs)