Unable to reproduce the issue on win-7 and win-10 using chrome reported version #70.0.3538.67 and latest canary #72.0.3592.0.
Attached a screen cast for reference.

Following are the steps followed to reproduce the issue.
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1. Opened index.html using a webserver.
2. Created and removed new <input> fields.
3. Observed that memory usage and number of DOM nodes stayed constant as expected.

reporter@ - Could you please check the attached screen cast and please let us know if anything missed from our end. Also please check the issue on latest canary #72.0.3592.0 by creating a new profile without any apps and extensions and please let us know if the issue still persist or not.

Thanks...!!

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Thanks for your reply.
All my tests were done with a profile without any apps or extensions. A college of mine can reproduce the issue on win-10 with chromium #72.0.3593.0.

But after watching the screen cast, I suspect we misunderstood.
For this issue it is mandatory to create and remove <input> FIELDS (not just the user input). I'm doing that with setIntervall for 10 seconds (see script in index.html).

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

I recorded the screen with Chromium #72.0.3595.2 on Ubuntu 18.04. I created a more complete example which additionally shows leaking is stopped after the password field was removed. The Steps of the test:
0) <0sec: start recording memory
1)  0sec: page refresh
2) GC triggered manually
3)  3sec: start to create and remove <input> fields (interval=300ms)
4) 13sec: stop interval (it runs 10000/300> 33 times)
5) GC triggered manually
6) 16sec: remove password field
7) GC triggered manually
8) 19sec: start to create and remove <input> fields (interval=300ms) (like step 3))
9) 29sec: stop interval (it runs 10000/300> 33 times)
10) GC triggered manually

Results:
- Number of DOM nodes increases from 25 to 73 (step 2 vs step 5).
- Old nodes are not removed after removing tge password field (step 5 vs step 7).
- After removing the password field the number of nodes stay constant 73 (step 7 vs step 10).

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As per comment #5 and comment #7, retried the issue on latest chromium 72.0.3610.0 using windows 10 and ubuntu 14.04.
Steps:
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1. Launched chromium  
2. Opened given index.html file using a web server 
3. Navigated to Dev tools > Performance > started recording 
4. Tried to click GC trigger manually 
As we are observed that the recording stops at 3 seconds 

@Reporter: Could you please check the attached screen cast and let us know if anything missed from our end. If possible provide any  inputs for further triaging it.

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	897644.mp4 5.4 MB View Download

Thanks for your reply.
Unfortunately our tests are very different: 
I described 10 steps (about 30 seconds).
Your test ended after step 2. You should use the other record button (and stop the recording manually after step 10).

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Able to reproduce the issue on reported chromium version #70.0.3538.0 and latest chromium #72.0.3622.0 using Mac 10.13.6, Windows 10 and Ubuntu 17.10.
Note: As we could not download the branch builds of chromium, hence checked on the above versions.

The behavior is seen from old M-60 builds(#60.0.3112.0). This is a non-regression issue, hence marking it as untriaged and requesting someone from the dev team to look into the issue.
Thanks.!