When rebaselining testharness tests with new all-PASS results, remove the baseline.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/models/testharness_results.py

 # Copyright 2014 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.
 
 """Utility module for testharness."""
 
 
 # const definitions
 TESTHARNESSREPORT_HEADER = 'This is a testharness.js-based test.'
 TESTHARNESSREPORT_FOOTER = 'Harness: the test ran to completion.'
 
 
+def is_all_pass_testharness_result(content_text):
+    """Returns whether |content_text| is a testharness result that only contains PASS lines."""
+    return (is_testharness_output(content_text) and
+            is_testharness_output_passing(content_text) and
+            not is_testharness_output_with_console_errors_or_warnings(content_text))
+
+
 def is_testharness_output(content_text):
     """Returns whether the content_text in parameter is a testharness output."""
 
     # Leading and trailing white spaces are accepted.
     lines = content_text.strip().splitlines()
     lines = [line.strip() for line in lines]
 
     # A testharness output is defined as containing the header and the footer.
     found_header = False
     found_footer = False
@@ skipping 62 matching lines @@
     Note:
         It is expected that the |content_text| is a testharness output.
     """
 
     lines = content_text.strip().splitlines()
     for line in lines:
         if line.startswith('CONSOLE ERROR:') or line.startswith('CONSOLE WARNING:'):
             return True
 
     return False