Issue 803113  has been merged into this issue.

About the drop down only having one value, preliminary debugging showed that
  getStringArray(R.array.distiller_mode_font_family_values)
strangely only return 1 element while 3 are expected.

For this particular issue, it's a recent regression. Known good: 65.0.3299.6 Dev, known bad: ToT. Could we get a bisect to know when this regression happened? Per revision would be nice.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c235742b6517d5dd02f80ad8caf2650af3033755

commit c235742b6517d5dd02f80ad8caf2650af3033755
Author: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Date: Thu Jan 18 23:58:14 2018

Improve appearance preference UI in reader mode

Larger margin between controls, larger touchable area of seeker,
and fixed drop-down menu with all items.

Bug:  803117 
Change-Id: Ic8b5b534aa684f09a5e28ad20685387fabc3eb23
Reviewed-on: https://chromium-review.googlesource.com/874753
Commit-Queue: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#530350}
[modify] https://crrev.com/c235742b6517d5dd02f80ad8caf2650af3033755/chrome/android/java/res/layout/distilled_page_prefs_view.xml
[delete] https://crrev.com/8a8bc0bc5a8fb97023d4a3469786f9c62f147fdb/chrome/android/java/res/values/arrays.xml
[modify] https://crrev.com/c235742b6517d5dd02f80ad8caf2650af3033755/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/DistilledPagePrefsView.java

The symptom is fixed by a workaround, but the issue about getStringArray() mentioned in #c2 is still there.

wychen@ -- Could you please provide a sample test file where the issue can be reproduced. It would help us in reproducing the issue and provide per-revision bisect.

Thanks!

To reproduce this issue:
- Go to chrome://flags and set "Reader Mode triggering" to "Always".
- Visit any page, and tap "Show mobile-friendly view".
- Tap menu, and tap appearance.

Expected: font drop down menu has 3 items.
Buggy state: the menu only has one item.

About drop down menu having only one item, it is tracked in issue 797626, so closing this one.