What's the future of browser plugin?

The plugin support by different browsers is diversifying and uncertain:

1. NPAPI was the most widely supported technology previously, but it is being deprecated by browser providers. Both Chrome, Firefox and Opera have or will drop support for NPAPI.
2. XPCOM is the technology adopted by Mozilla firefox. Javascript call XPCOM via XPConnect.
3. ActiveX is the Microsoft solution for plugin technology. Windows 8 and later contains a modern mode (formerly called Metro) of IE that disables almost all ActiveX controls.
4. FireBreath provide a solution to develop browser plugin in form of NPAPI or XPCOM. Since both NPAPI and ActiveX is going away, FireBreath needs change.

What's the future of Browser Plugin?