Known failures in the WebGL CTS 1.0.4, top of tree, using Chromium
https://www.khronos.org/registry/webgl/sdk/tests/webgl-conformance-tests.html

flaky:

conformance/canvas/framebuffer-bindings-affected-by-to-data-url.html: 2 tests failed (1 timed out)

failing:

conformance/context/user-defined-properties-on-context.html: 1 tests failed
conformance/glsl/bugs/pow-of-small-constant-in-user-defined-function.html: 1 tests failed
conformance/glsl/misc/const-variable-initialization.html: 207 tests failed
conformance/glsl/misc/struct-equals.html: 3 tests failed
conformance/glsl/misc/struct-specifiers-in-uniforms.html: 12 tests failed
conformance/glsl/misc/ternary-operators-in-global-initializers.html: 12 tests failed