oldGenGCCount property Null safety

1. Flutter
2. flutter_test
3. FrameTimingSummarizer
4. oldGenGCCount property

FrameTimingSummarizer class

1. Constructors
2. FrameTimingSummarizer
3. Properties
4. averageFrameBuildTime
5. averageFrameRasterizerTime
6. averageLayerCacheBytes
7. averageLayerCacheCount
8. averagePictureCacheBytes
9. averagePictureCacheCount
10. averageVsyncOverhead
11. frameBuildTime
12. frameRasterizerTime
13. hashCode
14. missedFrameBuildBudget
15. missedFrameRasterizerBudget
16. newGenGCCount
17. oldGenGCCount
18. p90FrameBuildTime
19. p90FrameRasterizerTime
20. p90LayerCacheBytes
21. p90LayerCacheCount
22. p90PictureCacheBytes
23. p90PictureCacheCount
24. p90VsyncOverhead
25. p99FrameBuildTime
26. p99FrameRasterizerTime
27. p99LayerCacheBytes
28. p99LayerCacheCount
29. p99PictureCacheBytes
30. p99PictureCacheCount
31. p99VsyncOverhead
32. runtimeType
33. summary
34. vsyncOverhead
35. worstFrameBuildTime
36. worstFrameRasterizerTime
37. worstLayerCacheBytes
38. worstLayerCacheCount
39. worstPictureCacheBytes
40. worstPictureCacheCount
41. worstVsyncOverhead
42. Methods
43. noSuchMethod
44. toString
45. Operators
46. operator ==