Add a run_eslint wrapper script

common/eslint/bin/run_eslint

 #!/usr/bin/env python
-
 # Copyright 2016 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.
 
 import os
 import sys
 
-_SYSTRACE_DIR = os.path.abspath(
+
+_ESLINT_PATH = os.path.abspath(
     os.path.join(os.path.dirname(__file__), os.path.pardir))
-sys.path.insert(0, _SYSTRACE_DIR)
-from systrace import run_systrace
+
+
+def _AddToPathIfNeeded(path):
+  if path not in sys.path:
+    sys.path.insert(0, path)
+
 
 if __name__ == '__main__':
-  sys.exit(run_systrace.main())
+  _AddToPathIfNeeded(_ESLINT_PATH)
+  from eslint import eslint
+
+  if len(sys.argv) == 1:
+    print eslint.RunEslintGlobal()
+  else:
+    print eslint.RunEslint(sys.argv[1:])