For Mac, set your tasks.json (in the .vscode folder) file contents to the following and use SHFT+COMMAND+B to open.
{
"version": "2.0.0",
"tasks": [
{
"label": "Chrome Preview",
"type": "shell",
"command": "open -a /Applications/Google\\ Chrome.app test.html",
"problemMatcher": [],
"group": {
"kind": "build",
"isDefault": true
}
}
]
}