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

conformance/context/user-defined-properties-on-context.html: 1 tests failed
conformance/extensions/ext-frag-depth.html: 1 tests failed
conformance/extensions/ext-shader-texture-lod.html: 1 tests failed
conformance/extensions/oes-standard-derivatives.html: 1 tests failed
conformance/glsl/bugs/pow-of-small-constant-in-user-defined-function.html: 1 tests failed
conformance/glsl/bugs/sampler-struct-function-arg.html: 1 tests failed
conformance/glsl/misc/const-variable-initialization.html: 207 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
deqp/data/gles2/shaders/constant_expressions.html: 4 tests failed
deqp/data/gles2/shaders/fragdata.html: 3 tests failed
deqp/data/gles2/shaders/functions.html: 14 tests failed
deqp/data/gles2/shaders/preprocessor.html: 41 tests failed
deqp/data/gles2/shaders/scoping.html: 12 tests failed
