The D3D bytecode IR generated by the HLSL shader compiler in the runtime isn't verified for security concerns before being passed to the driver, so there's no r

The D3D bytecode IR generated by the HLSL shader compiler in the runtime isn't verified for security concerns before being passed to the driver, so there's no real extra protection there, so ultimately D3D makes it no harder to lock the GPU than OpenGL (ES in the WebGL case) does.