[Telemetry] Reduce memory usage in presence of TraceValues

tools/telemetry/telemetry/benchmark.py

 # Copyright 2014 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 logging
 import optparse
 import os
 import shutil
 import sys
 import zipfile
@@ skipping 157 matching lines @@
     us = self.CreateUserStorySet(finder_options)
     if isinstance(pt, page_test.PageTest):
       if any(not isinstance(p, page.Page) for p in us.user_stories):
         raise Exception(
             'PageTest must be used with UserStorySet containing only '
             'telemetry.page.Page user stories.')
 
     self._DownloadGeneratedProfileArchive(finder_options)
 
     benchmark_metadata = self.GetMetadata()
-    results = results_options.CreateResults(benchmark_metadata, finder_options)
-    try:
-      user_story_runner.Run(pt, us, expectations, finder_options, results,
-                            max_failures=self._max_failures)
-      return_code = min(254, len(results.failures))
-    except Exception:
-      exception_formatter.PrintFormattedException()
-      return_code = 255
+    with results_options.CreateResults(benchmark_metadata,
+                                       finder_options) as results:
+      try:
+        user_story_runner.Run(pt, us, expectations, finder_options, results,
+                              max_failures=self._max_failures)
+        return_code = min(254, len(results.failures))
+      except Exception:
+        exception_formatter.PrintFormattedException()
+        return_code = 255
 
-    bucket = cloud_storage.BUCKET_ALIASES[finder_options.upload_bucket]
-    if finder_options.upload_results:
-      results.UploadTraceFilesToCloud(bucket)
-      results.UploadProfilingFilesToCloud(bucket)
+      bucket = cloud_storage.BUCKET_ALIASES[finder_options.upload_bucket]
+      if finder_options.upload_results:
+        results.UploadTraceFilesToCloud(bucket)
+        results.UploadProfilingFilesToCloud(bucket)
 
-    results.PrintSummary()
+      results.PrintSummary()
     return return_code
 
   def _DownloadGeneratedProfileArchive(self, options):
     """Download and extract profile directory archive if one exists."""
     archive_name = getattr(self, 'generated_profile_archive', None)
 
     # If attribute not specified, nothing to do.
     if not archive_name:
       return
 
@@ skipping 113 matching lines @@
     """
     return test_expectations.TestExpectations()
 
 
 def AddCommandLineArgs(parser):
   user_story_runner.AddCommandLineArgs(parser)
 
 
 def ProcessCommandLineArgs(parser, args):
   user_story_runner.ProcessCommandLineArgs(parser, args)