[test] Only run presubmit for changed status files

tools/presubmit.py

 #!/usr/bin/env python
 #
 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 443 matching lines @@
     keys = {}
     for key, value in pairs:
       if key in keys:
         print("%s: Error: duplicate key %s" % (filepath, key))
         status["success"] = False
       keys[key] = True
 
   json.loads(contents, object_pairs_hook=check_pairs)
   return status["success"]
 
-def CheckStatusFiles(workspace):
-  success = True
-  suite_paths = utils.GetSuitePaths(join(workspace, "test"))
-  for root in suite_paths:
-    suite_path = join(workspace, "test", root)
-    status_file_path = join(suite_path, root + ".status")
-    suite = testsuite.TestSuite.LoadTestSuite(suite_path)
-    if suite and exists(status_file_path):
+
+class StatusFilesProcessor(SourceFileProcessor):
+  """Checks status files for incorrect syntax and duplicate keys."""
+
+  def IsRelevant(self, name):
+    return name.endswith('.status')
+
+  def GetPathsToSearch(self):
+    return ['test']
+
+  def ProcessFiles(self, files):
+    success = True
+    for status_file_path in files:
       success &= statusfile.PresubmitCheck(status_file_path)
       success &= _CheckStatusFileForDuplicateKeys(status_file_path)
-  return success
+    return success
+
 
 def GetOptions():
   result = optparse.OptionParser()
   result.add_option('--no-lint', help="Do not run cpplint", default=False,
                     action="store_true")
   return result
 
 
 def Main():
   workspace = abspath(join(dirname(sys.argv[0]), '..'))
   parser = GetOptions()
   (options, args) = parser.parse_args()
   success = True
   print "Running C++ lint check..."
   if not options.no_lint:
     success &= CppLintProcessor().RunOnPath(workspace)
   print "Running copyright header, trailing whitespaces and " \
         "two empty lines between declarations check..."
   success &= SourceProcessor().RunOnPath(workspace)
-  success &= CheckStatusFiles(workspace)
+  print "Running status-files check..."
+  success &= StatusFilesProcessor().RunOnPath(workspace)
   if success:
     return 0
   else:
     return 1
 
 
 if __name__ == '__main__':
   sys.exit(Main())