ANGLE converts OpenGL ES 2 or 3 calls to DirectX 9, 11, or OpenGL calls. These instructions document how to use ANGLE instead of the native OpenGL backend on Windows or Linux.
gclient sync downloads ANGLE's source alongside Skia's other test-only dependencies.
ANGLE is built when building Skia test tools on Windows and Linux.
When running tools, use --config angle_<backend>_<frontend>, e.g.
out/Debug/dm --src gm --config angle_d3d11_es2 out/Release/nanobench --config angle_gl_es2