Make AffectedFile usable as items.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/118521

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@18076 0039d316-1c4b-4281-b951-d872f2087c98

presubmit_support.py

@@ -89,7 +89,7 @@ class OutputApi(object):
       output_stream.write(self._message)
       output_stream.write('\n')
       for item in self._items:
-        output_stream.write('  %s\n' % item)
+        output_stream.write('  %s\n' % str(item))
       if self._long_text:
         output_stream.write('\n***************\n%s\n***************\n' %
                             self._long_text)
@@ -435,6 +435,9 @@ class AffectedFile(object):
     """
     raise NotImplementedError()  # Implement if/when needed.
 
+  def __str__(self):
+    return self.LocalPath()
+
 
 class SvnAffectedFile(AffectedFile):
   """Representation of a file in a change out of a Subversion checkout."""