When using Handles.DrawCamera to draw camera view on another window, rescaling that window results in a Game view camera scale change as well(inspect attached gif)

Steps to reproduce:
1. Open attached window
2. Go to window -> Test window
3. Select "Main Camera" in the hierarchy (camera should start rendering in "Test window")
4. Scale "Test window" height
-Camera in "Game view" also gets rescaled

Actual result: Every scaling that is done on "Test window" effects "Game view" as well.
Expected result: Scaling "Test window" should not result in a "Game view" changes.

Reproduced on: 5.5.0b4, 5.4.1f1, 5.3.6p5, 5.2.3p3