Split web_dev_style tests into separate files.

chrome/browser/web_dev_style/test_util.py

Index: chrome/browser/web_dev_style/test_util.py
diff --git a/chrome/browser/web_dev_style/test_util.py b/chrome/browser/web_dev_style/test_util.py
new file mode 100644
index 0000000000000000000000000000000000000000..a613d75d8e8e0af57a78334303fc3b33a4b842bf
--- /dev/null
+++ b/chrome/browser/web_dev_style/test_util.py
@@ -0,0 +1,10 @@
+# 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')
+  highlight = error_lines[error_lines.index(line) + 1]
+  return ''.join(ch1 for (ch1, ch2) in zip(line, highlight) if ch2 == '^')