Whether the tab has produced sound over the past couple of seconds (but it
might not be heard if also muted). Equivalent to whether the 'speaker
audio' indicator is showing.
Whether the tab is discarded. A discarded tab is one whose content has
been unloaded from memory, but is still visible in the tab strip. Its
content is reloaded the next time it is activated.
The URL of the tab's favicon. This property is only present if the
extension's manifest includes the "tabs" permission. It may also be an
empty string if the tab is loading.
The ID of the tab. Tab IDs are unique within a browser session. Under some
circumstances a tab may not be assigned an ID; for example, when querying
foreign tabs using the sessions API, in which case a session ID may be
present. Tab ID can also be set to chrome.tabs.TAB_ID_NONE for apps and
devtools windows.
The URL the tab is navigating to, before it has committed. This property
is only present if the extension's manifest includes the "tabs"
permission and there is a pending navigation.
The last committed URL of the main frame of the tab. This property is only
present if the extension's manifest includes the "tabs" permission and
may be an empty string if the tab has not yet committed. See also
Tab.pendingUrl.