This test is already fails every 2-4 builds on Mac Pro AMD.

Example build: https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac%20Pro%20FYI%20Release%20%28AMD%29/2255

It seems that something is wrong in the command buffer validation because the following can be seen in the logs for the test:

[8012:775:0820/123614.618429:ERROR:gles2_cmd_decoder.cc(6633)] [.WebGL-0x7fbf0a808e00]GL ERROR :GL_INVALID_OPERATION : glGenerateMipmap: Can not generate mips
[8012:775:0820/123614.625076:ERROR:gles2_cmd_decoder.cc(6633)] [.WebGL-0x7fbf0a808e00]GL ERROR :GL_INVALID_OPERATION : glGenerateMipmap: Can not generate mips
[8012:775:0820/123614.628037:ERROR:gles2_cmd_decoder.cc(6633)] [.WebGL-0x7fbf0a808e00]GL ERROR :GL_INVALID_OPERATION : glGenerateMipmap: Can not generate mips

And the test doesn't expect any GL_INVALID_OPERATION