lint: Initialize logger inside zulint.

This also helps move verbose_timing logic inside zulint.

tools/lint

@@ -1,7 +1,6 @@
 #!/usr/bin/env python3
 from __future__ import print_function
 from __future__ import absolute_import
-import logging
 import os
 import sys
 import argparse
@@ -67,13 +66,6 @@ def run():
     # Invoke the appropriate lint checker for each language,
     # and also check files for extra whitespace.
 
-    logging.basicConfig(format="%(asctime)s %(message)s")
-    logger = logging.getLogger()
-    if args.verbose_timing:
-        logger.setLevel(logging.INFO)
-    else:
-        logger.setLevel(logging.WARNING)
-
     linter_config = LinterConfig(by_lang)
     linter_config.external_linter('add_class', ['tools/find-add-class'], ['js'])
     linter_config.external_linter('css', ['node', 'node_modules/.bin/stylelint'], ['css', 'scss'])

tools/zulint/command.py

@@ -114,6 +114,15 @@ class LinterConfig:
 
         self.lint_functions[name] = run_linter
 
+    def set_logger(self, verbose_timing):
+        # type: (bool) -> None
+        logging.basicConfig(format="%(asctime)s %(message)s")
+        logger = logging.getLogger()
+        if verbose_timing:
+            logger.setLevel(logging.INFO)
+        else:
+            logger.setLevel(logging.WARNING)
+
     def do_lint(self, args):
         # type: (argparse.Namespace) -> None
         assert not args.only or not args.skip, "Only one of --only or --skip can be used at once."
@@ -124,6 +133,7 @@ class LinterConfig:
         if args.list:
             print("\n".join(self.lint_functions.keys()))
             sys.exit()
+        self.set_logger(args.verbose_timing)
 
         failed = run_parallel(self.lint_functions)
         sys.exit(1 if failed else 0)