[Py3] Get tools/testrunner/testproc closer to Py3

This modernizes python code without breaking Py2 compat.

Ran with command:

futurize --stage1 -w tools/testrunner/testpro

Manual fixup to util_unittest to modify import paths and change to
absolute imports.

Bug: v8:9871
Change-Id: I2ac29622aff5daebc9dc42145c1d96dff8258546
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2252549Reviewed-by: Tamer Tas <tmrts@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68492}

tools/testrunner/testproc/progress.py

@@ -4,6 +4,7 @@
 
 # for py2/py3 compatibility
 from __future__ import print_function
+from __future__ import absolute_import
 
 import datetime
 import json
@@ -12,7 +13,7 @@ import platform
 import subprocess
 import sys
 import time
-import util
+from . import util
 
 from . import base
 

tools/testrunner/testproc/timeout.py

+from __future__ import print_function
 # Copyright 2018 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

tools/testrunner/testproc/util_unittest.py

@@ -3,9 +3,18 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-from util import FixedSizeTopList
+from __future__ import absolute_import
+
+import os
+import sys
 import unittest
 
+TOOLS_PATH = os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.abspath(__file__))))
+sys.path.append(TOOLS_PATH)
+
+from testrunner.testproc.util import FixedSizeTopList
+
 class TestOrderedFixedSizeList(unittest.TestCase):
   def test_empty(self):
     ofsl = FixedSizeTopList(3)