Loading maps for the first time is too slow

[jayantchens]

mapbox-gl-js version:0.38.0

Steps to Trigger Behavior

1.I used the official mapbox://styles/mapbox/light-v9 to set map styles and found initialization was too slow to load maps.
2.Finds that you always ask for a certain type of PBF format file（）

Expected Behavior

  Load maps as quickly as possible

Actual Behavior

  **Open Network,found a lot of requests for .pbf**  
  **For example, many similar requests url：** (https://api.mapbox.com/fonts/v1/mapbox/Open%20Sans%20Semibold,Arial%20Unicode%20MS%20Bold/39168-39423.pbf?access_token=pk.eyJ1IjoiY2hlbmp1bnlhbiIsImEiOiJjaXh6aHE3enIwMDR2MzNvN2YwMmZvMDlyIn0.2Cy8Z_qvQ1IGKpqASmZjtA )

[jfirebaugh]

Hi @JunYanchan, thanks for the report. We're aware that loading glyph PBFs for CJK languages is a performance issue in network-constrained environments. We're tracking this in #3466.

[jayantchens]

@jfirebaugh Thank you. I read the article, but it doesn't seem to explain how it works. Can you tell me the specific usage? Developing mapbox GL.js (javaScript) on the web web page?