UserAgent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.84 Safari/537.36

Steps to reproduce the problem:
1. Use the WebDriver to inject JS Code (I'm using Nigthwatch.JS/Selenium)
2. Click Elements or test visibility

What is the expected behavior?
Remote control should not have an significant or permanent impact on the used memory.

What went wrong?
Each action (like a click) in Nightwatch.JS permanently occupies memory in Chrome. The strings are hold due to "source" reference of compiled code.
I'm trying to test a large application with memory leaks for a few days. Unfortunately, the injected strings block several 100MB after some time.
The images shows the situation after a few seconds running time.

Did this work before? N/A 

Chrome version: 68.0.3440.84  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: 

I tried to comprehend this problem by creating a minimal example:
1. Open blank webpage
2. Write in console: console.log("Hallo")
3. Try to free that memory:
  - clear Console
  - clear console history
  - remove all snapshots
  - close and reopen devTools
  - trigger GC
  - occupy more and more memory (until the 4GB tab limit, because I heard the "compile code cache" is reduced if too much memory is in use)

I'm not able to free the memory, which was allocated due to the console input.
 

Deleted: chrome_nightwatchMemory.PNG 394 KB

	chrome_nightwatchMemory.PNG 394 KB View Download