Update buildbots to parse new telemetry JSON format.

scripts/slave/telemetry_utils.py

+#! /usr/bin/env python
+# Copyright (c) 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.
+# pylint: disable=R0201
+
+"""Log parsing for telemetry tests."""
+
+import json
+import logging
+import os
+import tempfile
+
+
+class TelemetryResultsTracker(object):
+
+  def __init__(self):
+    self._chart_filename = None
+    self._ref_chart_filename = None
+
+  def GetArguments(self):
+    if not self._chart_filename:
+      (handle, self._chart_filename) = tempfile.mkstemp()
+      os.close(handle)
+    if not self._ref_chart_filename:
+      (handle, self._ref_chart_filename) = tempfile.mkstemp()
+      os.close(handle)
+    return (['--chart-output-filename', self._chart_filename,
+             '--ref-output-filename', self._ref_chart_filename])
+
+  def _GetFileJson(self, filename):
+    try:
+      return json.loads(open(filename).read())
+    except (IOError, ValueError):
+      logging.error('Error reading telemetry results from %s', filename)
+      return None
+
+  def ChartJson(self):
+    return self._GetFileJson(self._chart_filename)
+
+  def RefJson(self):
+    return self._GetFileJson(self._ref_chart_filename)
+
+  def Cleanup(self):
+    try:
+      os.remove(self._chart_filename)
+    except OSError:
+      pass
+    try:
+      os.remove(self._ref_chart_filename)
+    except OSError:
+      pass
+
+  def IsChartJson(self):
+    """This is the new telemetry --chartjson output format."""
+    return True
+
+  def ProcessLine(self, line):
+    pass
+
+  def FailedTests(self):
+    return []
+
+  def SuppressionHashes(self):  # pylint: disable=R0201
+    return []
+
+  def ParsingErrors(self):  # pylint: disable=R0201
+    return []
+
+  def PerformanceSummary(self):
+    return ''