Add a git command for running ToT WebKit patches against the trybots.

This is basically a wrapper script for running a WebKit change against
the try bots.  It can be run from within third_party/WebKit and will try to apply the patch against ToT WebKit.

This tells the try server we want to use ToT WebKit by passing third_party/WebKit@HEAD as the first line of the patch file.

BUG=None
Review URL: https://codereview.chromium.org/12226013

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@181972 0039d316-1c4b-4281-b951-d872f2087c98

git-wktry

+#!/bin/sh
+# Copyright (c) 2013 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.
+
+# Test if this script is running under a MSys install.  If it is, we will
+# hardcode the path to Python where possible.
+OUTPUT="$(uname | grep 'MINGW')"
+MINGW=$?
+
+if [ $MINGW = 0 ]; then
+  base_dir="${0%\\*}"
+else
+  base_dir=$(dirname "$0")
+fi
+
+if [ -d "$base_dir/python_bin" -a $MINGW = 0 ]; then
+  PYTHONDONTWRITEBYTECODE=1 exec "$base_dir/python_bin/python.exe" "$base_dir"/git_wktry.py "$@"
+else
+  PYTHONDONTWRITEBYTECODE=1 exec "$base_dir/git_wktry.py" "$@"
+fi

git_wktry.py

+#!/usr/bin/python
+# Copyright (c) 2013 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.
+"""Wrapper for trychange.py for WebKit changes."""
+
+import errno
+import logging
+import os
+import sys
+import tempfile
+
+import git_cl
+from scm import GIT
+import trychange
+
+
+class ScopedTemporaryFile(object):
+  def __init__(self, **kwargs):
+    file_handle, self._path = tempfile.mkstemp(**kwargs)
+    os.close(file_handle)
+
+  def __enter__(self):
+    return self._path
+
+  def __exit__(self, type, value, traceback):
+    try:
+      os.remove(self._path)
+    except OSError, e:
+      if e.errno != errno.ENOENT:
+        raise e
+
+
+def generateDiff(path_to_write, chromium_src_root):
+  """Create the diff file to send to the try server. We prepend the WebKit
+  revision to the beginning of the diff so we can patch against ToT or other
+  versions of WebKit."""
+  diff_lines = ['third_party/WebKit@HEAD\n']
+
+  raw_diff = GIT.GenerateDiff(os.path.join(chromium_src_root,
+      'third_party/WebKit'), full_move=True).splitlines(True)
+  diff_lines.extend(trychange.GetMungedDiff('third_party/WebKit',
+      raw_diff)[0])
+
+  open(path_to_write, 'wb').write(''.join(diff_lines))
+
+
+def addLayoutBotsIfNeeded(argv):
+  for flag in argv:
+    if flag == '--bot' or flag.startswith('--bot=') or flag.startswith('-b'):
+      return argv
+  argv.extend(('--bot', 'linux_layout_rel,mac_layout_rel,win_layout_rel'))
+
+
+def chromiumSrcRoot():
+  root = GIT.GetCheckoutRoot('.')
+  parent_path, leaf_path = os.path.split(root)
+  if leaf_path == 'WebKit':
+    root = GIT.GetCheckoutRoot(parent_path)
+  return root
+
+
+def main(argv):
+  chromium_src_root = chromiumSrcRoot()
+  os.chdir(chromium_src_root)
+  argv = argv[1:]
+  addLayoutBotsIfNeeded(argv)
+
+  with ScopedTemporaryFile() as diff_file:
+    generateDiff(diff_file, chromium_src_root)
+    args = [
+        '--sub_rep', 'third_party/WebKit',
+        '--root', 'src',
+        '--rietveld_url', 'https://codereview.chromium.org',
+        '--diff', diff_file,
+    ]
+    args.extend(argv)
+    cl = git_cl.Changelist()
+    change = cl.GetChange(cl.GetUpstreamBranch(), None)
+    logging.getLogger().handlers = []
+    return trychange.TryChange(args, change,
+        swallow_exception=False, prog='git wktry')
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))