Telemetry: Move TimeoutException from util module to exceptions module.

tools/perf/metrics/startup_metric.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 collections
 import json
 import logging
 
 from metrics import Metric
 
-from telemetry.core import util
+from telemetry.core import exceptions
 from telemetry.value import histogram_util
 from telemetry.value import scalar
 
 
 class StartupMetric(Metric):
   "A metric for browser startup time."
 
   HISTOGRAMS_TO_RECORD = {
     'messageloop_start_time' :
         'Startup.BrowserMessageLoopStartTimeFromMainEntry',
@@ skipping 46 matching lines @@
 
         perf_timing = t.EvaluateJavaScript('window.performance.timing')
         if 'requestStart' not in perf_timing:
           perf_timing['requestStart'] = 0  # Exclude from benchmark results
           print 'requestStart is not supported by this browser'
 
         tab_load_times.append(TabLoadTime(
             int(result['load_start_ms']),
             int(result['load_duration_ms']),
             int(perf_timing['requestStart'])))
-      except util.TimeoutException:
+      except exceptions.TimeoutException:
         # Low memory Android devices may not be able to load more than
         # one tab at a time, so may timeout when the test attempts to
         # access a background tab. Ignore these tabs.
         logging.error("Tab timed out on JavaScript access")
 
     # Only measure the foreground tab. We can't measure all tabs on Android
     # because on Android the data of the background tabs is loaded on demand,
     # when the user switches to them, rather than during startup. In view of
     # this, to get the same measures on all platform, we only measure the
     # foreground tab on all platforms.
@@ skipping 29 matching lines @@
 
       results.AddValue(scalar.ScalarValue(
           results.current_page, display_name, 'ms', measured_time))
 
     # Get tab load times.
     browser_main_entry_time_ms = self._GetBrowserMainEntryTime(tab)
     if (browser_main_entry_time_ms is None):
       print "Outdated Chrome version, browser main entry time not supported."
       return
     self._RecordTabLoadTimes(tab, browser_main_entry_time_ms, results)