Add input_api.logging.

This makes it possible to dump logging information from a PRESUBMIT script when
calling git cl presubmit -v -v -v for example.

R=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/7027031

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@87603 0039d316-1c4b-4281-b951-d872f2087c98

presubmit_canned_checks.py

@@ -600,6 +600,8 @@ def RunPylint(input_api, output_api, white_list=None, black_list=None):
     # were listed, try to run pylint.
     try:
       from pylint import lint
+      input_api.logging.debug(
+          'Using pylint v%s from %s' % (lint.version, lint.__file__))
     except ImportError:
       if input_api.platform == 'win32':
         return [output_api.PresubmitNotifyResult(

presubmit_support.py

@@ -243,6 +243,7 @@ class InputApi(object):
     self.cPickle = cPickle
     self.cStringIO = cStringIO
     self.json = json
+    self.logging = logging.getLogger('PRESUBMIT')
     self.os_listdir = os.listdir
     self.os_walk = os.walk
     self.os_path = os.path

tests/presubmit_unittest.py

@@ -793,7 +793,8 @@ class InputApiUnittest(PresubmitTestsBase):
       'LocalToDepotPath',
       'PresubmitLocalPath', 'ReadFile', 'RightHandSideLines', 'ServerPaths',
       'basename', 'cPickle', 'cStringIO', 'canned_checks', 'change', 'environ',
-      'host_url', 'is_committing', 'json', 'marshal', 'os_listdir', 'os_walk',
+      'host_url', 'is_committing', 'json', 'logging', 'marshal', 'os_listdir',
+      'os_walk',
       'os_path', 'owners_db', 'pickle', 'platform', 'python_executable', 're',
       'rietveld', 'subprocess', 'tbr', 'tempfile', 'time', 'traceback',
       'unittest', 'urllib2', 'version', 'verbose',