Description:
Recently I found the text alignment for Latin and CJK Ideographs are different between Firefox and LibreOffice when I use vertical layout

Steps to Reproduce:
1. Open https://wymeditor.github.io/wymeditor/dist/examples/01-basic.html in Firefox, input 世界你好 Hello, World! in there and use writing-mode: vertical-rl property
2. Create Writer Document in LibreOffice, input the same text, then using LTR (vertical) direction for the page.

Actual Results:  
On Firefox the left edge of CJK Ideographs aligned with beard line (https://en.wikipedia.org/wiki/Descender), on LibreOffice, the left edge of CJK Ideographs aligned with baseline.

Expected Results:
When vertical layout enabled, CJK texts should always align with beard line. See my attachment.


Reproducible: Always

User Profile Reset: No

Additional Info:
Version: 5.3.0.0.alpha1+
Build ID: 05d2a66955f8a6552a79696474386ca9f45f9ef2
CPU Threads: 4; OS Version: Windows 6.2; UI Render: default; Layout Engine: new; 
TinderBox: Win-x86@62-merge-TDF, Branch:MASTER, Time: 2016-11-07_23:34:48
Locale: zh-CN (zh_CN); Calc: group


User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:49.0) Gecko/20100101 Firefox/49.0