Alter hooks to call into depot_tools lib....

git-cl-upload-hook

 #!/usr/bin/python
 # Copyright (c) 2009 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 re
-import subprocess
 import sys
 
 # Find depot_tools in PATH, append it to sys.path so we can import.
 paths = os.environ.get("PATH")
 for path in paths.split(':'):
   if not path.endswith("depot_tools"):
     continue
   sys.path.append(path)
   break
 
-import gclient_scm
-import presubmit_support
-
-def Backquote(cmd, cwd=None):
-  """Like running `cmd` in a shell script."""
-  return subprocess.Popen(cmd,
-                          cwd=cwd,
-                          stdout=subprocess.PIPE).communicate()[0].strip()
-
-
-class ChangeOptions:
-  def __init__(self, commit=None, upstream_branch=None):
-    self.commit = commit
-    self.verbose = None
-    self.default_presubmit = None
-    self.may_prompt = None
-
-    root = os.path.abspath(Backquote(['git', 'rev-parse', '--show-cdup']))
-    if not root:
-      raise Exception("Could not get root directory.")
-    log = Backquote(['git', 'show', '--name-only',
-                     '--pretty=format:%H%n%s%n%n%b'])
-    m = re.match(r'^(\w+)\n(.*)$', log, re.MULTILINE|re.DOTALL)
-    if not m:
-      raise Exception("Could not parse log message: %s" % log)
-    name = m.group(1)
-    description = m.group(2)
-    files = gclient_scm.CaptureGitStatus([root], upstream_branch)
-    issue = Backquote(['git', 'cl', 'status', '--field=id'])
-    patchset = None
-    self.change = presubmit_support.GitChange(name, description, root, files,
-                                              issue, patchset)
-
+import git_cl_hooks
 
 # Ensure we were called with the necessary number of arguments.
 program_name = os.path.basename(sys.argv[0])
-if len(sys.argv) < 2:
+if len(sys.argv) != 2:
   raise Exception("usage: %s [upstream branch]" % program_name)
 
-# Get arguments from how we were called.
-commit = (program_name == 'pre-cl-dcommit')
-upstream_branch = sys.argv[1]
-
-# Create our options based on the command-line args and the current checkout.
-options = ChangeOptions(commit=commit, upstream_branch=upstream_branch)
-
-# Run the presubmit checks.
-if presubmit_support.DoPresubmitChecks(options.change,
-                                       options.commit,
-                                       options.verbose,
-                                       sys.stdout,
-                                       sys.stdin,
-                                       options.default_presubmit,
-                                       options.may_prompt):
-  sys.exit(0)
-else:
-  sys.exit(1)
+# Run the hooks library with our arguments.
+exec git_cl_hooks.RunHooks(hook_name=program_name, upstream_branch=sys.argv[1])