Event fired when the capture status of a tab changes.
This allows extension authors to keep track of the capture status of
tabs to keep UI elements like page actions in sync.
|info| : CaptureInfo with new capture status for the tab.
Captures the visible area of the currently active tab. Capture can
only be started on the currently active tab after the extension has been
invoked, similar to the way that
activeTab works.
Capture is maintained across page navigations within
the tab, and stops when the tab is closed, or the media stream is closed
by the extension.
Returns a list of tabs that have requested capture or are being
captured, i.e. status != stopped and status != error.
This allows extensions to inform the user that there is an existing
tab capture that would prevent a new tab capture from succeeding (or
to prevent redundant requests for the same tab).
|callback| : Callback invoked with CaptureInfo[] for captured tabs.
Creates a stream ID to capture the target tab.
Similar to chrome.tabCapture.capture() method, but returns a media
stream ID, instead of a media stream, to the consumer tab.
