webgl disabled in qt5.10.1 and cef3

[wander]

i use qt5.10.1 and cef3 to make an appication with webgl. but always get the err of webgl disabled.
i also define the commandline in cef3,it's no use.
command_line->AppendSwitchWithValue("enable-webgl", "1");
command_line->AppendSwitchWithValue("ignore-gpu-blacklist", "1");
command_line->AppendSwitchWithValue("allow-file-access-from-files", "1");

and if i do not use qt frame, it works.

Do i need to define other parameters or flags in qt?
Help!