Manifest v3

[Libor Polčák]

Hello  Giorgio,

I went through 
https://developer.chrome.com/docs/extensions/mv3/intro/mv3-migration/ with the 
intention of identifying required changes to support Manifest v3:

* Background script -> service workers
  * We will not have the possibility to keep any state, this will affect 
Network Boundary Shield (NBS), we cannot prepare code in advance, and there 
will be probably more breakage like updating badges when switching tabs.
  * We might need to revert 6b51fa8606c71b5057471e1a91fd7ffc410a019a which 
improved the reliability of the wrappings being applied before page scripts 
start executing.

* Web Request API -> Declarative Net Requests
  * Right now only NBS is affected (so far I think that NBS will need to be 
removed from chromium-based browsers),
  * The blocking strategy based on heuristics that I explained on one of the 
calls will be affected and most likely impossible to im=plement.

* getURL is beeing removed - several instances, mostly needed for NBS.

* we are ussing connect/sendMassage/onconnect/onMessage for communication 
between popup and background, in NBS, and also in Firefox-only code dealing 
with the bug 1267027.

Giorgio, I do not see any removal of document_start content scripts which is 
the core functionality of the extension.

Did I miss something?

Libor