Examine source code of Convert Case

{
  "name": "__MSG_extName__",
  "description": "__MSG_extDescription__",
  "default_locale": "en",
  "version": "2.4.2",
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{356d3987-45f1-4dd6-8fc2-4f03189e8812}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "logo/16.png",
    "48": "logo/48.png",
    "128": "logo/icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "https://*/*",
        "http://*/*"
      ],
      "js": [
        "/content/main.js"
      ]
    }
  ],
  "browser_action": {
    "default_title": "__MSG_popupTitle__",
    "default_popup": "popup.html",
    "default_icon": "logo/icon.png"
  },
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage",
    "contextMenus",
    "activeTab",
    "tabs",
    "<all_urls>"
  ],
  "commands": {
    "lowercase": {
      "suggested_key": {
        "default": "Alt+L"
      },
      "description": "__MSG_cmd_lowercase__"
    },
    "uppercase": {
      "suggested_key": {
        "default": "Alt+U"
      },
      "description": "__MSG_cmd_uppercase__"
    },
    "capitalizedcase": {
      "suggested_key": {
        "default": "Alt+C"
      },
      "description": "__MSG_cmd_capitalizedcase__"
    },
    "titlecase": {
      "suggested_key": {
        "default": "Alt+A"
      },
      "description": "__MSG_cmd_titlecase__"
    },
    "sentencecase": {
      "description": "__MSG_cmd_sentencecase__"
    },
    "alternatingcase": {
      "description": "__MSG_cmd_alternatingcase__"
    },
    "inversecase": {
      "description": "__MSG_cmd_inversecase__"
    },
    "slugify": {
      "description": "__MSG_cmd_slugify__"
    },
    "camelcase": {
      "description": "__MSG_cmd_camelcase__"
    },
    "pascalcase": {
      "description": "__MSG_cmd_pascalcase__"
    },
    "snakecase": {
      "description": "__MSG_cmd_snakecase__"
    },
    "constantcase": {
      "description": "__MSG_cmd_constantcase__"
    },
    "dotcase": {
      "description": "__MSG_cmd_dotcase__"
    },
    "pathcase": {
      "description": "__MSG_cmd_pathcase__"
    },
    "noaccents": {
      "description": "__MSG_cmd_noaccents__"
    },
    "nocase": {
      "description": "__MSG_cmd_nocase__"
    }
  }
}