pef(Listeners): not removed

[rbalet]

Bug Report or Feature Request (mark with an x)

- [ ] Regression (a behavior that used to work and stopped working in a new release)
- [x] Bug report -> please search issues before submitting
- [ ] Feature request
- [ ] Documentation issue or request

Description

Actually, when we change the pdf without removing the pdfViewer, the listeners & node are not removed.

Step to reproduce

1. ng s the project
2. Start recording performance on google dev tool
3. Change the file multiple time

Result

Here you can clearly see that the Nodes and Listeners aren't cleared