Clone Chromium's depot_tools repository:

git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git

Add the absolute path of the cloned directory to the end of your PATH variable (You may want to put this in ~/.bashrc or ~/.zshrc.). Assuming you cloned depot_tools to /path/to/depot_tools:

export PATH=$PATH:/path/to/depot_tools

Create a browser-android-tabs parent directory:

mkdir browser-android-tabs

Switch to the directory you just created:

cd browser-android-tabs

Clone the repository to the src subdirectory:

git clone https://github.com/brave/browser-android-tabs.git src

Switch to the directory you just cloned:

cd src

Execute the scripts/getThirdParties.js script:

sh scripts/getThirdParties.js

Enter information as requested by the script. When asked to create a file for arguments, use this gn file.

From the browser-android-tabs/src directory, execute the following:

ninja -C out/Default chrome_public_apk

Deploy it to your Android device:

build/android/adb_install_apk.py out/Default/apks/Brave.apk

Create configuration in a new folder:

gn args out/DefaultR

Set these settings in args.gn file.

From the browser-android-tabs/src directory, execute the following:

ninja -C out/DefaultR chrome_public_apk

Sign apk using these steps.

Create configuration in a new folder:

gn args out/Defaultx86

Set these settings in args.gn file.

From the browser-android-tabs/src directory, execute the following:

ninja -C out/Defaultx86 chrome_public_apk

Sign apk using these steps.