Pass mb_mastername and mb_buildername as parameters to override the default.

scripts/slave/recipe_modules/filter/api.py

Index: scripts/slave/recipe_modules/filter/api.py
diff --git a/scripts/slave/recipe_modules/filter/api.py b/scripts/slave/recipe_modules/filter/api.py
index 359c2a41fd41ff613af68a88497effc3d021f945..52246ffd3a9206ecb3bd5830a95f31ed2d0254ab 100644
--- a/scripts/slave/recipe_modules/filter/api.py
+++ b/scripts/slave/recipe_modules/filter/api.py
@@ -69,6 +69,8 @@ class FilterApi(recipe_api.RecipeApi):
 
   def does_patch_require_compile(self,
                                  affected_files,
+                                 mb_mastername,
+                                 mb_buildername,
                                  test_targets=None,
                                  additional_compile_targets=None,
                                  additional_names=None,
@@ -82,6 +84,8 @@ class FilterApi(recipe_api.RecipeApi):
     Args:
       affected_files: list of files affected by the current patch; paths
                       should only use forward slashes ("/") on all platforms
+      mb_mastername: the mastername to pass over to run MB.
+      mb_buildername: the buildername to pass over to run MB.
       test_targets: the possible set of executables that are desired to run.
                     When done, test_targets() returns the subsetset of targets
                     that are affected by the files that have changed.
@@ -91,6 +95,11 @@ class FilterApi(recipe_api.RecipeApi):
                         see |config_file_name|.
       conconfig_file_name: the config file to look up exclusions in.
 
+    For `mb_mastername` and `mb_buildername`, they are the actual mastername and
+    buildername we're running on, and not those of the continuous builder the
+    trybot may configured to match, because a trybot may be configured with
+    different MB settings.
+
     Within the file we concatenate "base.exclusions" and
     "|additional_names|.exclusions" (if |additional_names| is not none) to
     get the full list of exclusions.
@@ -165,9 +174,9 @@ class FilterApi(recipe_api.RecipeApi):
           self.m.path['checkout'].join('tools', 'mb', 'mb.py'),
           args=['analyze',
                 '-m',
-                self.m.properties['mastername'],
+                mb_mastername,
                 '-b',
-                self.m.properties['buildername'],
+                mb_buildername,
                 '-v',
                 build_output_dir,
                 self.m.json.input(analyze_input),