Android supported WebGL from 5.0, and I encountered some 5.0 devices not supported in the actual development, the original chromium to run GPUs unstable or compatibility problems of the device will disable WebGL.
On the Android platform you can access Chrome://gpu by installing Chorme Browser, find reset notification strategy This configuration item does turn off WEBGL support, if the value is 0x8252 it supports WEBGL, If the value is 0x0000, the device is blacklisted.
The device in the blacklist to support WebGL, can be crosswalk, add configuration Items Xwalk--ignore-gpu-blacklist Implementation, the specific use of the crosswalk official website.
Crosswalk Official website: https://crosswalk-project.org/
Configuration See Canvas and WebGL support, URL: https://crosswalk-project.org/documentation/about/faq.html
Original
Android WebView Support WebGL