Potential leaks detected while splitting setting editor

[mjbvz]

Issue Type: Bug

Repo

1. In a new VS Code instance
2. Open the settings editor
3. Split the settings editor and then close the newly split editor
4. Repeate this a few times

Bug
I'm seeing a few different potential leaks being reported:

[5d8] potential listener LEAK detected, having 214 listeners already. MOST frequent listener (15):
event.ts:435     at new t (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2009:534)
    at t._createView (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2046:677)
    at t._attachModel (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2044:231)
    at t.setModel (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2027:178)
    at t [as constructor] (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2699:16)
    at t.create (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:229:596)
    at t.e._createInstance (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:1506:215)
    at t.e.createInstance (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:1505:561)
    at t.createHeader (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:4086:567)
    at t.createEditor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:4083:266)
    at t.create (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2663:541)
    at t.doCreateEditorControl (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:3825:442)
    at t.doShowEditorControl (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:3825:46)
    at t.openEditor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:3824:765)
    at t.doShowEditor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:5330:565)
    at t.doOpenEditor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:5330:453)
    at t.openEditor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:5329:878)
    at t.doMoveOrCopyEditorAcrossGroups (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:5332:362)
    at t.copyEditor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:5332:494)
    at Object.C [as splitEditor] (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:4273:730)
    at t.run (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:4284:38)
    at file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2576:57

[5d8] potential listener LEAK detected, having 253 listeners already. MOST frequent listener (23):
 at e (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2269:982)
    at t.create (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:229:596)
    at t.e._createInstance (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:1506:215)
    at t.e.createInstance (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:1505:561)
    at file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:2284:432
    at e._executor (file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:113:41)
    at file:///Applications/Visual Studio Code - Insiders.app/Contents/Resources/app/out/vs/workbench/workbench.main.js:113:135

VS Code version: Code - Insiders 1.31.0-insider (acc7365, 2019-01-29T06:13:57.866Z)
OS version: Darwin x64 18.2.0

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-4770HQ CPU @ 2.20GHz (8 x 2200)
GPU Status	2d_canvas: enabled checker_imaging: disabled_off flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: enabled rasterization: enabled surface_synchronization: enabled_on video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	3, 3, 3
Memory (System)	16.00GB (0.04GB free)
Process Argv
Screen Reader	no
VM	22%

[roblourens]

I found one leak but it's neither of these

[roblourens]

I could never repro this but I will keep an eye open.