Examine source code of Copy+Switch

{
  "manifest_version": 2,
  "name": "Copy+Switch",
  "version": "1.1resigned1",
  "description": "Copy+Switch extension allows you to switch the currently selected text with the previously copied text. The switch can only be performed between text fields.\n\nAfter copying some text from a text field, select a portion of text in another text field and then simply 'Right Click -> Switch' or use the keyboard shortcut 'Ctrl+Shift+V' ('Cmd+Shift+V' on Mac)",
  "icons": {
    "48": "assets/images/icon48.png"
  },
  "background": {
    "scripts": [
      "build/js/background.js"
    ]
  },
  "content_scripts": [
    {
      "js": [
        "build/js/content.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true
    }
  ],
  "permissions": [
    "contextMenus"
  ],
  "commands": {
    "switch-selection": {
      "suggested_key": {
        "default": "Ctrl+Shift+V"
      },
      "description": "Switch the currently selected text with the previously copied text"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a13c877d-13cb-4182-9b92-9c1667fcf3f8}"
    }
  }
}