[tools/perf] Reference legacy_page_test module instead of page_test

tools/perf/measurements/rasterize_and_record_micro.py

 # Copyright 2013 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.
 
 import time
 
 from telemetry.core import exceptions
-from telemetry.page import page_test
+from telemetry.page import legacy_page_test
 from telemetry.value import scalar
 
 
-class RasterizeAndRecordMicro(page_test.PageTest):
+class RasterizeAndRecordMicro(legacy_page_test.LegacyPageTest):
 
   def __init__(self, start_wait_time=2, rasterize_repeat=100, record_repeat=100,
                timeout=120, report_detailed_results=False):
     super(RasterizeAndRecordMicro, self).__init__()
     self._chrome_branch_number = None
     self._start_wait_time = start_wait_time
     self._rasterize_repeat = rasterize_repeat
     self._record_repeat = record_repeat
     self._timeout = timeout
     self._report_detailed_results = report_detailed_results
@@ skipping 23 matching lines @@
                   window.benchmark_results.done = true;
                   window.benchmark_results.results = value;
                 }, {
                   "record_repeat_count": %i,
                   "rasterize_repeat_count": %i
                 });
     """ % (self._record_repeat, self._rasterize_repeat))
 
     benchmark_id = tab.EvaluateJavaScript('window.benchmark_results.id')
     if not benchmark_id:
-      raise page_test.MeasurementFailure(
+      raise legacy_page_test.MeasurementFailure(
           'Failed to schedule rasterize_and_record_micro')
 
     tab.WaitForJavaScriptExpression(
         'window.benchmark_results.done', self._timeout)
 
     data = tab.EvaluateJavaScript('window.benchmark_results.results')
 
     pixels_recorded = data['pixels_recorded']
     record_time = data['record_time_ms']
     pixels_rasterized = data['pixels_rasterized']
@@ skipping 78 matching lines @@
           results.current_page, 'total_layers', 'count', total_layers))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_picture_layers', 'count',
           total_picture_layers))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_picture_layers_with_no_content', 'count',
           total_picture_layers_with_no_content))
       results.AddValue(scalar.ScalarValue(
           results.current_page, 'total_picture_layers_off_screen', 'count',
           total_picture_layers_off_screen))