终端滚动距离问题

[dahai331]

Issue Type: Bug

在终端的界面里面，用滑轮滚动的时候非常不平滑，界面小的时候会看不到很多内容，而且有终端的历史数据丢失的现象

VS Code version: Code 1.38.1 (b37e54c, 2019-09-11T13:35:15.005Z)
OS version: Windows_NT x64 10.0.18956

System Info

Item	Value
CPUs	Intel(R) Core(TM) i5-8300H CPU @ 2.30GHz (8 x 2304)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software oop_rasterization: disabled_off protected_video_decode: enabled rasterization: enabled skia_deferred_display_list: disabled_off skia_renderer: disabled_off surface_synchronization: enabled_on video_decode: enabled viz_display_compositor: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	7.86GB (2.91GB free)
Process Argv	C:\Users\asus\Desktop\python_algorithm
Screen Reader	no
VM	40%

[Tyriar]

/duplicate xtermjs/xterm.js#1140