luckysmg 948e1fa81a [iOS][Keyboard] Wait vsync on UI thread and update viewport inset to avoid jitter. (flutter/engine#42312) ...

Video for after and before this patch:
[videos.zip](https://github.com/flutter/engine/files/11231756/videos.zip)

- https://github.com/flutter/flutter/issues/120555

The technical problem is: if setViewportMetrics called **before** framework's vsync process callback (rebuild & layout & paint), will cause jitter keyboard animation.So this PR is to keep the time when updateViewportMetrics call to framework side legal.

### Before
![2](https://github.com/flutter/engine/assets/49340347/71198a08-b139-4d6d-87e1-37e536f5d34b)

### After
![1](https://github.com/flutter/engine/assets/49340347/5c9df757-7e39-4855-8c3a-009f5d6438b2)

2023-06-13 17:40:05 +00:00

..

src/flutter

[iOS][Keyboard] Wait vsync on UI thread and update viewport inset to avoid jitter. (flutter/engine#42312)

2023-06-13 17:40:05 +00:00