chrome.contextMenus API to add items to Google Chrome's context
menu. You can choose what types of objects your context menu additions apply
to, such as images, hyperlinks, and pages.
- The different contexts a menu can appear in. Specifying 'all' is equivalent to the combination of all other contexts except for 'launcher'. The 'launcher' context is only supported by apps and is used to add menu items to the context menu that appears when clicking on the app icon in the launcher/taskbar/dock/etc. Different platforms might put limitations on what is actually supported in a launcher context menu.
- The type of menu item.