SpeechSynthesis class

1. Properties
2. paused
3. pending
4. speaking
5. hashCode
6. on
7. runtimeType
8. Methods
9. cancel
10. getVoices
11. pause
12. resume
13. speak
14. addEventListener
15. dispatchEvent
16. noSuchMethod
17. removeEventListener
18. toString
19. Operators
20. operator ==