Unittest for page_runner, etc. should suppress output from gtest_progress_reporter

tools/telemetry/telemetry/results/gtest_progress_reporter.py

Index: tools/telemetry/telemetry/results/gtest_progress_reporter.py
diff --git a/tools/telemetry/telemetry/results/gtest_progress_reporter.py b/tools/telemetry/telemetry/results/gtest_progress_reporter.py
index 96b2608a18640318ad81172183b29b91588a010b..93e053de80c7ac8ce42aa57145eea527bb09b5cf 100644
--- a/tools/telemetry/telemetry/results/gtest_progress_reporter.py
+++ b/tools/telemetry/telemetry/results/gtest_progress_reporter.py
@@ -13,7 +13,8 @@ class GTestProgressReporter(progress_reporter.ProgressReporter):
   """A progress reporter that outputs the progress report in gtest style."""
 
   def __init__(self, output_stream, output_skipped_tests_summary=False):
-    super(GTestProgressReporter, self).__init__(output_stream)
+    super(GTestProgressReporter, self).__init__()
+    self._output_stream = output_stream
     self._timestamp = None
     self._output_skipped_tests_summary = output_skipped_tests_summary
 
@@ -24,11 +25,11 @@ class GTestProgressReporter(progress_reporter.ProgressReporter):
   def DidAddValue(self, value):
     super(GTestProgressReporter, self).DidAddValue(value)
     if isinstance(value, failure.FailureValue):
-      print >> self.output_stream, failure.GetStringFromExcInfo(
+      print >> self._output_stream, failure.GetStringFromExcInfo(
           value.exc_info)
-      self.output_stream.flush()
+      self._output_stream.flush()
     elif isinstance(value, skip.SkipValue):
-      print >> self.output_stream, '===== SKIPPING TEST %s: %s =====' % (
+      print >> self._output_stream, '===== SKIPPING TEST %s: %s =====' % (
           value.page.display_name, value.reason)
     # TODO(chrishenry): Consider outputting metric values as well. For
     # e.g., it can replace BuildbotOutputFormatter in
@@ -37,31 +38,31 @@ class GTestProgressReporter(progress_reporter.ProgressReporter):
 
   def WillRunPage(self, page_test_results):
     super(GTestProgressReporter, self).WillRunPage(page_test_results)
-    print >> self.output_stream, '[ RUN      ]', (
+    print >> self._output_stream, '[ RUN      ]', (
         page_test_results.current_page.display_name)
-    self.output_stream.flush()
+    self._output_stream.flush()
     self._timestamp = time.time()
 
   def DidRunPage(self, page_test_results):
     super(GTestProgressReporter, self).DidRunPage(page_test_results)
     page = page_test_results.current_page
     if page_test_results.current_page_run.failed:
-      print >> self.output_stream, '[  FAILED  ]', page.display_name, (
+      print >> self._output_stream, '[  FAILED  ]', page.display_name, (
           '(%0.f ms)' % self._GetMs())
     else:
-      print >> self.output_stream, '[       OK ]', page.display_name, (
+      print >> self._output_stream, '[       OK ]', page.display_name, (
           '(%0.f ms)' % self._GetMs())
-    self.output_stream.flush()
+    self._output_stream.flush()
 
   def WillAttemptPageRun(self, page_test_results, attempt_count, max_attempts):
     super(GTestProgressReporter, self).WillAttemptPageRun(
         page_test_results, attempt_count, max_attempts)
     # A failed attempt will have at least 1 value.
     if attempt_count != 1:
-      print >> self.output_stream, (
+      print >> self._output_stream, (
           '===== RETRYING PAGE RUN (attempt %s out of %s allowed) =====' % (
               attempt_count, max_attempts))
-      print >> self.output_stream, (
+      print >> self._output_stream, (
           'Page run attempt failed and will be retried. '
           'Discarding previous results.')
 
@@ -76,24 +77,24 @@ class GTestProgressReporter(progress_reporter.ProgressReporter):
         successful_runs.append(run)
 
     unit = 'test' if len(successful_runs) == 1 else 'tests'
-    print >> self.output_stream, '[  PASSED  ]', (
+    print >> self._output_stream, '[  PASSED  ]', (
         '%d %s.' % (len(successful_runs), unit))
     if len(failed_runs) > 0:
       unit = 'test' if len(failed_runs) == 1 else 'tests'
-      print >> self.output_stream, '[  FAILED  ]', (
+      print >> self._output_stream, '[  FAILED  ]', (
           '%d %s, listed below:' % (len(page_test_results.failures), unit))
       for failed_run in failed_runs:
-        print >> self.output_stream, '[  FAILED  ] ', (
+        print >> self._output_stream, '[  FAILED  ] ', (
             failed_run.page.display_name)
-      print >> self.output_stream
+      print >> self._output_stream
       count = len(failed_runs)
       unit = 'TEST' if count == 1 else 'TESTS'
-      print >> self.output_stream, '%d FAILED %s' % (count, unit)
-    print >> self.output_stream
+      print >> self._output_stream, '%d FAILED %s' % (count, unit)
+    print >> self._output_stream
 
     if self._output_skipped_tests_summary:
       if len(page_test_results.skipped_values) > 0:
-        print >> self.output_stream, 'Skipped pages:\n%s\n' % ('\n'.join(
+        print >> self._output_stream, 'Skipped pages:\n%s\n' % ('\n'.join(
             v.page.display_name for v in page_test_results.skipped_values))
 
-    self.output_stream.flush()
+    self._output_stream.flush()