Examine source code of Auto Tab Discard

{
  "manifest_version": 2,
  "version": "0.6.7",
  "name": "Auto Tab Discard",
  "description": "__MSG_app_description__",
  "default_locale": "en",
  "icons": {
    "16": "data/icons/16.png",
    "32": "data/icons/32.png",
    "48": "data/icons/48.png",
    "64": "data/icons/64.png",
    "128": "data/icons/128.png",
    "256": "data/icons/256.png",
    "512": "data/icons/512.png"
  },
  "storage": {
    "managed_schema": "schema.json"
  },
  "permissions": [
    "idle",
    "storage",
    "contextMenus",
    "notifications",
    "alarms",
    "*://*/*"
  ],
  "background": {
    "page": "background.html"
  },
  "content_scripts": [
    {
      "match_about_blank": true,
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "data/inject/watch.js"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "options_ui": {
    "page": "data/options/index.html",
    "open_in_tab": true
  },
  "homepage_url": "https://webextension.org/listing/tab-discard.html",
  "commands": {
    "discard-tab": {
      "description": "__MSG_cmd_discard_tab__"
    },
    "discard-tree": {
      "description": "__MSG_cmd_discard_tree__"
    },
    "discard-window": {
      "description": "__MSG_cmd_discard_window__"
    },
    "discard-other-windows": {
      "description": "__MSG_cmd_discard_other_windows__"
    },
    "discard-tabs": {
      "description": "__MSG_cmd_discard_tabs__"
    },
    "move-previous": {
      "description": "__MSG_cmd_move_previous__"
    },
    "move-next": {
      "description": "__MSG_cmd_move_next__"
    },
    "close": {
      "description": "__MSG_cmd_close__"
    },
    "_execute_browser_action": {}
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c2c003ee-bd69-42a2-b0e9-6f34222cb046}"
    }
  },
  "browser_action": {
    "default_popup": "data/popup/index.html"
  }
}