Function read_devtools_active_port_from 

pub fn read_devtools_active_port_from(
    data_dir: &Path,
) -> Result<(u16, String), ChromeError>

Read the DevToolsActivePort file from a specific directory.

This is the parameterized version of read_devtools_active_port that accepts an explicit data directory, enabling unit testing without relying on platform-specific defaults.

Errors

Returns ChromeError::NoActivePort if the file is missing or unreadable, or ChromeError::ParseError if the contents are malformed.