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

chrome/test/vr/perf/BUILD.gn

+# 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.
+
+group("motopho_latency_test") {
+  testonly = true
+  data = [
+    "./latency/__init__.py",
+    "./latency/android_webvr_latency_test.py",
+    "./latency/motopho_thread.py",
+    "./latency/robot_arm.py",
+    "./latency/run_latency_test.py",
+    "./latency/webvr_latency_test.py",
+    "//third_party/android_tools/sdk/platform-tools/adb",
+    "//third_party/gvr-android-sdk/test-apks/vr_services/vr_services_current.apk",
+  ]
+  data_deps = [
+    "//chrome/android:chrome_public_apk",
+  ]
+}