1. broadcastchannel api: `broadcastchannel()` constructor

2. broadcastchannel api: close

3. broadcastchannel api: `messageerror` event

4. broadcastchannel api: `message` event

5. broadcastchannel api: name

6. broadcastchannel api: postmessage

7. document api: requeststorageaccess: `types` parameter: `types.broadcastchannel` parameter

8. storageaccesshandle api: broadcastchannel