1. 构造函数
2. MediaSource
3. 属性
4. activeSourceBuffers
5. duration
6. hashCode
7. on
8. readyState
9. runtimeType
10. sourceBuffers
11. 方法
12. addEventListener
13. addSourceBuffer
14. clearLiveSeekableRange
15. dispatchEvent
16. endOfStream
17. noSuchMethod
18. removeEventListener
19. removeSourceBuffer
20. setLiveSeekableRange
21. toString
22. 运算符
23. 运算符 ==
24. 静态属性
25. supported
26. 静态方法
27. isTypeSupported