Move chrome/browser/web_dev_style/ to tools/ to use from more places

chrome/browser/web_dev_style/test_util.py

-# Copyright 2015 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.
-
-
-def GetHighlight(line, error):
-  """Returns the substring of |line| that is highlighted in |error|."""
-  error_lines = error.split('\n')
-  # TODO(dschuyler): Splitting the error on \n will prevent index(line)
-  # from finding the line. As a workaround, return the whole, unfiltered
-  # line.
-  if line not in error_lines:
-    return line
-  highlight = error_lines[error_lines.index(line) + 1]
-  return ''.join(ch1 for (ch1, ch2) in zip(line, highlight) if ch2 == '^')