[Telemetry] Move failure reasoning into summary.py.

Previously, we were having Summary take a boolean had_failures. Now that
failures are part of Telemetry's value system, it is easy to have Summary
reason about how to summarize values when failures and/or skips are present.
This CL is the first step: it eliminates had_failures from being passed around
and instead computes it directly based on the presence of failures in the
passed list of page-specific values.

Review URL: https://codereview.chromium.org/465063002

Cr-Commit-Position: refs/heads/master@{#289556}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289556 0039d316-1c4b-4281-b951-d872f2087c98

tools/telemetry/telemetry/results/buildbot_output_formatter.py

@@ -31,8 +31,7 @@ class BuildbotOutputFormatter(output_formatter.OutputFormatter):
     # Print out the list of unique pages.
     perf_tests_helper.PrintPages(
         [page.display_name for page in page_test_results.pages_that_succeeded])
-    summary = summary_module.Summary(page_test_results.all_page_specific_values,
-                                     had_failures)
+    summary = summary_module.Summary(page_test_results.all_page_specific_values)
     for value in summary.interleaved_computed_per_page_values_and_summaries:
       if value.page:
         self._PrintComputedPerPageValue(value)

tools/telemetry/telemetry/value/summary.py

@@ -35,7 +35,9 @@ class Summary(object):
       ]
 
   """
-  def __init__(self, all_page_specific_values, had_failures):
+  def __init__(self, all_page_specific_values):
+    had_failures = any(isinstance(v, failure.FailureValue) for v in
+        all_page_specific_values)
     self.had_failures = had_failures
     self._computed_per_page_values = []
     self._computed_summary_values = []