Window size increases slightly for each new window

[riastradh-brave]

Description

Each new window is one or two pixels higher than the one in focus when it was opened.

Steps to Reproduce

1. Open a window and move it to a definite height (e.g., flush against the top of the screen).
2. Open a new window and move it to a definite height.
3. With a magnifying glass, scrutinize the bottom and see that the window size is slightly larger.

(My magnifying glass does not exist, and my eyeballs lack the resolution to discriminate one pixel from two pixels on this high-resolution display.)

Actual result:

Expected result:

Reproduces how often:

100%

Brave version (brave://version info)

Brave	0.68.60 Chromium: 75.0.3770.90 (Official Build)nightly (64-bit)
Revision	a6dcaf7e3ec6f70a194cc25e8149475c6590e025-refs/branch-heads/3770@{#1003}
OS	Linux
JavaScript	V8 7.5.288.23
Flash	(Disabled)
User Agent	Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.90 Safari/537.36
Command Line	/usr/bin/brave-browser-nightly --enable-dom-distiller --disable-domain-reliability --disable-chrome-google-url-tracking-client --no-pings --extensions-install-verification=enforce_strict --enable-features=NewExtensionUpdaterService,DesktopPWAWindowing,SimplifyHttpsIndicator --disable-features=AutofillSaveCardSignInAfterLocalSave,AutofillServerCommunication,NetworkService,UnifiedConsent --flag-switches-begin --flag-switches-end
Executable Path	/opt/brave.com/brave-nightly/brave-browser-nightly
Profile Path	/home/riastradh/.config/BraveSoftware/Brave-Browser-Nightly/Default
Variations	d74ef32b-f693abd7

Version/Channel Information:

• Can you reproduce this issue with the current release?
  • yes
• Can you reproduce this issue with the beta channel?
  • yes
• Can you reproduce this issue with the dev channel?
  • yes
• Can you reproduce this issue with the nightly channel?
  • yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
  • no
• Does the issue resolve itself when disabling Brave Rewards?
  • no
• Is the issue reproducible on the latest version of Chrome?
  • no

Miscellaneous Information:

• This could serve as a fingerprinting vector.
• I am relieved to confirm, in verifying this bug, that I am not crazy, at least not in the way I thought I was about my slightly different window sizes.