handle OWNERS suggestions where anyone can approve better.

owners.py

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A database of OWNERS files.
 
 OWNERS files indicate who is allowed to approve changes in a specific directory
 (or who is allowed to make changes without needing approval of another OWNER).
 Note that all changes must still be reviewed by someone familiar with the code,
 so you may need approval from both an OWNER and a reviewer in many cases.
@@ skipping 103 matching lines @@
     # Set of paths that stop us from looking above them for owners.
     # (This is implicitly true for the root directory).
     self.stop_looking = set([''])
 
   def reviewers_for(self, files):
     """Returns a suggested set of reviewers that will cover the files.
 
     files is a sequence of paths relative to (and under) self.root."""
     self._check_paths(files)
     self._load_data_needed_for(files)
-    return self._covering_set_of_owners_for(files)
+    suggested_owners = self._covering_set_of_owners_for(files)
+    if EVERYONE in suggested_owners:
+      if len(suggested_owners) > 1:
+        suggested_owners.remove(EVERYONE)
+      else:
+        suggested_owners = set(['<anyone>'])
+    return suggested_owners
 
   # TODO(dpranke): rename to objects_not_covered_by
   def directories_not_covered_by(self, files, reviewers):
     """Returns the set of directories that are not owned by a reviewer.
 
     Determines which of the given files are not owned by at least one of the
     reviewers, then returns a set containing the applicable enclosing
     directories, i.e. the ones upward from the files that have OWNERS files.
 
     Args:
@@ skipping 168 matching lines @@
         if num_directories_owned:
           total_costs_by_owner[owner] = (total_distance /
                                          pow(num_directories_owned, 1.75))
 
     # Return the lowest cost owner. In the case of a tie, pick one randomly.
     lowest_cost = min(total_costs_by_owner.itervalues())
     lowest_cost_owners = filter(
       lambda owner: total_costs_by_owner[owner] == lowest_cost,
       total_costs_by_owner)
     return random.Random().choice(lowest_cost_owners)