Make VR sample page names match dashboard

Replaces characters that are unsupported by the performance dashboard
with underscores in benchmarks that use WebVR and WebXR sample pages.
This is so that the name reported on the dashboard can actually be
used as a story filter when bisecting.

Bug: 881017
Change-Id: Ifae260815a1382ce5dcab9e393ad8b0344ab0f86
Reviewed-on: https://chromium-review.googlesource.com/c/1252848Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596025}

tools/perf/contrib/vr_benchmarks/vr_sample_page.py

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import os
+import re
 from telemetry import page
 from contrib.vr_benchmarks import (shared_android_vr_page_state as
                                    vr_state)
@@ -26,6 +27,13 @@ class _VrXrSamplePage(page.Page):
     if url_parameters is not None:
       url += '?' + '&'.join(url_parameters)
     name = url.replace('.html', '')
+    # Replace characters that are unsupported by the perf dashboard here so that
+    # the name reported on the dashboard can be used as a story filter.
+    # We don't use a the \W+ regex like other benchmarks because we need to
+    # keep certain non-alphanumeric characters around for backwards naming
+    # compatibility. This regex should replace anything except alphanumeric,
+    # question mark, dash, and period characters with underscores.
+    name = re.sub(r'[^a-zA-Z\d\?\-\.]+', '_', name)
     url = 'file://' + os.path.join(sample_directory, url)
     super(_VrXrSamplePage, self).__init__(
         url=url,