[4.0.0-rc.5] Mask incorrect after screen resize

[leemanhopeter]

Version

• Phaser Version: 4.0.0-rc.5

Description

There are two problems:

1. if a container uses its child as a mask, it will sometimes be rendered wrong
2. after screen resize and changing a mask's size, it will sometimes be rendered wrong

Example Test Code

https://phaser.io/sandbox/iK75nyU8

To see the first problem, load the example code above, see what it is like, comment out line 23, uncomment line 24, notice that the results are not the same, but they should be

To see the second problem, use a desktop browser to load the example code, resize the browser window by dragging a corner of the browser window, you will notice that when you are dragging, the image will sometimes become brighter, stop dragging when the image becomes brighter, you will notice that as the mask resizes, the things outside of the mask are still visible