[tools/perf] Delete unused variable

tools/perf/measurements/v8_gc_times.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 telemetry.page import page_test
 from telemetry.timeline.model import TimelineModel
 from telemetry.timeline import tracing_config
 from telemetry.util import statistics
 from telemetry.value import scalar
 
 
 class V8GCTimes(page_test.PageTest):
 
   _TIME_OUT_IN_SECONDS = 60
   _CATEGORIES = ['blink.console',
                  'renderer.scheduler',
                  'v8',
                  'webkit.console']
   _RENDERER_MAIN_THREAD = 'CrRendererMain'
   _IDLE_TASK_PARENT = 'SingleThreadIdleTaskRunner::RunTask'
 
   def __init__(self):
     super(V8GCTimes, self).__init__()
 
   def WillNavigateToPage(self, page, tab):
+    del page  # unused
     config = tracing_config.TracingConfig()
     for category in self._CATEGORIES:
       config.tracing_category_filter.AddIncludedCategory(category)
     config.enable_chrome_trace = True
     tab.browser.platform.tracing_controller.StartTracing(
         config, self._TIME_OUT_IN_SECONDS)
 
   def ValidateAndMeasurePage(self, page, tab, results):
+    del page  # unused
     trace_data = tab.browser.platform.tracing_controller.StopTracing()
     timeline_model = TimelineModel(trace_data)
     renderer_process = timeline_model.GetRendererProcessFromTabId(tab.id)
     self._AddV8MetricsToResults(renderer_process, results)
 
   def DidRunPage(self, platform):
     if platform.tracing_controller.is_tracing_running:
       platform.tracing_controller.StopTracing()
 
   def _AddV8MetricsToResults(self, process, results):
@@ skipping 185 matching lines @@
     self.count = 0
 
   @property
   def thread_duration_outside_idle(self):
     return self.thread_duration - self.thread_duration_inside_idle
 
   @property
   def percentage_thread_duration_during_idle(self):
     return statistics.DivideIfPossibleOrZero(
         100 * self.thread_duration_inside_idle, self.thread_duration)