Examine source code of Gecko Code Coverage

{
  "author": "Marco Castelluccio",
  "manifest_version": 2,
  "name": "Gecko Code Coverage",
  "version": "0.11.0",
  "icons": {
    "270": "assets/coverage.jpg"
  },
  "description": "Extension that augments several Mozilla websites (DXR, Searchfox) with code coverage information.",
  "content_scripts": [
    {
      "matches": [
        "*://dxr.mozilla.org/mozilla-central/source/*"
      ],
      "js": [
        "build/dxr.js"
      ],
      "css": [
        "src/spinner.css",
        "src/dxr.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "*://searchfox.org/mozilla-central/source/*"
      ],
      "js": [
        "build/searchfox.js"
      ],
      "css": [
        "src/spinner.css",
        "src/dxr.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "*://crash-stats.mozilla.com/report/index/*"
      ],
      "js": [
        "build/socorro.js"
      ],
      "css": [
        "src/spinner.css",
        "src/socorro.css"
      ],
      "run_at": "document_end"
    },
    {
      "matches": [
        "*://hg.mozilla.org/mozilla-central/file/*",
        "*://hg.mozilla.org/mozilla-central/annotate/*"
      ],
      "js": [
        "build/hgmo.js"
      ],
      "css": [
        "src/spinner.css",
        "src/dxr.css"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "https://coverage.moz.tools/v2/*",
    "https://mapper.mozilla-releng.net/gecko-dev/rev/git/*",
    "https://hg.mozilla.org/mozilla-central/json-rev/*"
  ],
  "homepage_url": "https://github.com/mozilla/code-coverage-addon"
}