chromium/third_party/blink/web_tests/external/wpt/webvtt/categories.json

{
    ":categories": [
        ["api", "parsing", "rendering"],
        ["cues"],
        ["regions"],
        ["stylesheets"]
    ],
    ":subcategories": ["api/categories.json", "parsing/categories.json"],
    "api/*": "api",
    "parsing/*": "parsing",
    "rendering/*": "rendering"
}