[tools/perf] Reference legacy_page_test module instead of page_test

tools/perf/measurements/blink_style.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.
 
 from collections import defaultdict
 from itertools import starmap
 from telemetry.core import exceptions
 from telemetry.core import util
-from telemetry.page import page_test
+from telemetry.page import legacy_page_test
 from telemetry.value import scalar
 
 from measurements import timeline_controller
 
 
-class BlinkStyle(page_test.PageTest):
+class BlinkStyle(legacy_page_test.LegacyPageTest):
 
   def __init__(self):
     super(BlinkStyle, self).__init__()
     self._controller = None
 
   def WillNavigateToPage(self, page, tab):
     self._controller = timeline_controller.TimelineController()
     self._controller.trace_categories = 'blink_style,blink.console'
     self._controller.SetUp(page, tab)
     self._controller.Start(tab)
@@ skipping 109 matching lines @@
       tokens = sum(event.tokens for event in events)
       length = sum(event.length for event in events)
 
       results.AddValue(
           scalar.ScalarValue(page, ('parse_css_%s' % category),
                              'tokens/s', 1000 / (parse_duration / tokens)))
 
       results.AddValue(
           scalar.ScalarValue(page, ('tokenize_css_%s' % category),
                              'char/s',  1000 / (tokenize_duration / length)))