Make VR latency results compatible with perf dashboard, refactor into classes

chrome/test/vr/perf/latency/motopho_thread.py

+# Copyright 2017 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 subprocess
+import threading
+
+class MotophoThread(threading.Thread):
+  """Handles the running of the Motopho script and extracting results."""
+  def __init__(self):
+    threading.Thread.__init__(self)
+    self._latency = None
+    self._max_correlation = None
+
+  def run(self):
+    motopho_output = ""
+    try:
+      motopho_output = subprocess.check_output(["./motophopro_nograph"],
+                                               stderr=subprocess.STDOUT)
+    except subprocess.CalledProcessError as e:
+      logging.error('Failed to run Motopho script: %s', e.output)
+      raise e
+
+    if "FAIL" in motopho_output:
+      logging.error('Failed to get latency, logging raw output: %s',
+                    motopho_output)
+      raise RuntimeError('Failed to get latency - correlation likely too low')
+
+    self._latency = None
+    self._max_correlation = None
+    for line in motopho_output.split("\n"):
+      if 'Motion-to-photon latency:' in line:
+        self._latency = float(line.split(" ")[-2])
+      if 'Max correlation is' in line:
+        self._max_correlation = float(line.split(' ')[-1])
+      if self._latency and self._max_correlation:
+        break;
+
+  @property
+  def latency(self):
+    return self._latency
+
+  @property
+  def max_correlation(self):
+    return self._max_correlation