Chrome and Firefox use ANGLE (almost its own graphics layer engine), which creates OpenGL ES 2 on top of Direct3D 9 to implement WebGL.
According to the ANGLE website, "Chrome uses ANGLE for all Windows graphics, including the accelerated implementation of Canvas2D and Sandbox for its own client."
So when you ask if Chrome uses DirectX or OpenGL ... the only real way to answer this is with Frankenstein's monster. This is a bit and , and ultimately they want OpenGL ES to be the basic graphics subsystem, but since it is not available on Windows, they decided to launch a project in which ES layers are on top of D3D9.
This seems like a silly approach to me, since OpenGL would be even easier to stack on top of it. Unsurprisingly, many people reported that they received significantly better WebGL performance by disabling ANGLE and switching using their own OpenGL to Win32.
source share