For whatever reason, Chrome on Windows doesn’t scroll tabs by mouse wheel.

The generally accepted solution is an AutoHotKey script, published on Google Drive, which works for maximized Chrome windows. That’s good enough for me.

However, this cannot work in conjunction with the “Scroll inactive windows” feature of AltDrag (another thing you quickly miss from Linux). Therefore, I had to add that functionality to my AutoHotkey.ahk. This is the result:

SendMode Input  ; Recommended for new scripts due to its superior speed and reliability.

;;
; xmodmap -option ctrl:nocaps
;
^+!Capslock::Capslock
Capslock::Control

;; 
; Mouse Wheel Tab Scroll 4 Chrome
; -------------------------------
; Scroll though Chrome tabs with your mouse wheel when hovering over the tab bar.
; If the Chrome window is inactive when starting to scroll, it will be activated.
;   https://plus.google.com/115670442023408995787/posts/WYPqqk2j9UB
;   https://drive.google.com/drive/folders/0ByBbgFg_gObJTmdFd29PWEVwVHc

; updated to include inactive window scrolling with the help of
;  https://autohotkey.com/board/topic/6292-send-mouse-scrolls-to-window-under-mouse/?p=52004

WheelUp::
WheelDown::
    MouseGetPos,, ypos, id
    WinGetClass, class, ahk_id %id%
    If (ypos < 45 and InStr(class,"Chrome_WidgetWin"))
    {
        IfWinNotActive ahk_id %id%
            WinActivate ahk_id %id%
        If A_ThisHotkey = WheelUp
            Send ^{PgUp}
        Else
            Send ^{PgDn}
    }
    Else
    {
        IfWinNotActive ahk_id %id%
        {
            MouseGetPos m_x, m_y, WinID, Ctrl
            PostMessage 0x20A,((A_ThisHotKey="WheelUp")-.5)*(120<<16),(m_y<<16)|m_x,%Ctrl%,ahk_id %WinID%
        }
        Else
        {
            If A_ThisHotkey = WheelUp
                Send {WheelUp}
            Else
                Send {WheelDown}
        }
    }
    ReturnCode language: AutoHotkey (autohotkey)