Add automated VR latency tester

chrome/test/vr/automated_motopho_latency/BUILD.gn

Index: chrome/test/vr/automated_motopho_latency/BUILD.gn
diff --git a/chrome/test/vr/automated_motopho_latency/BUILD.gn b/chrome/test/vr/automated_motopho_latency/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..6fb0f38a38c844bceb0540d4fc0253feee1de281
--- /dev/null
+++ b/chrome/test/vr/automated_motopho_latency/BUILD.gn
@@ -0,0 +1,13 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.

[Lei Lei, 2017/04/07 21:36:34]

How about constructing the folder as following:
chrome
  test
    vr
      perf
         latency
           <all files about latency tests here>

[bsheedy, 2017/04/07 23:24:52]

Done.

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+group("automated_motopho_latency_test") {

[Lei Lei, 2017/04/07 21:36:35]

I prefer to remove automated prefix to short the name, since it is pretty clear
this is not manual tests.

[bsheedy, 2017/04/07 23:24:51]

Done.

+  testonly = true
+  data = [
+    "./run_latency_test.py",
+  ]
+  data_deps = [
+    "//chrome/android:chrome_public_apk",
+  ]
+}