[Telemetry] Fix exception handling for blink_styles and rasterize_and_record use of WaitFor

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 legacy_page_test
 from telemetry.value import scalar
 
+import py_utils
 
 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
 
   def CustomizeBrowserOptions(self, options):
     options.AppendExtraBrowserArgs([
         '--enable-gpu-benchmarking'
     ])
 
   def ValidateAndMeasurePage(self, page, tab, results):
     del page  # unused
     try:
       tab.WaitForDocumentReadyStateToBeComplete()
-    except exceptions.TimeoutException:
+    except py_utils.TimeoutException:
       pass
     time.sleep(self._start_wait_time)
 
     # Enqueue benchmark
     tab.ExecuteJavaScript("""
         window.benchmark_results = {};
         window.benchmark_results.done = false;
         window.benchmark_results.id =
             chrome.gpuBenchmarking.runMicroBenchmark(
                 "rasterize_and_record_benchmark",
@@ skipping 91 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))