Add background for bar groups

I've found a workaround by using the grid lines as background. This way it doesn't change it's background - it's always gray. Not great but looks OK so far.

documentclass{article}
usepackage[utf8]{inputenc}
usepackage[table,xcdraw,rgb,svgnames]{xcolor}
usepackage{tikz, pgfplots}
usetikzlibrary{shapes,shapes.multipart,arrows,positioning,matrix,fit,backgrounds,calc}

begin{document}

    begin{tikzpicture}
        tikzset{font=tiny}
        pgfplotstableread{%
        x   chromepc-rust   chromepc-go firefoxpc-rust  firefoxpc-go    chromemobile-rust
        Base64      92.85   80.45       87.91   47.39       84.82
        Sort        59.08   -63.30      76.24   32.35       45.22
        SHA256      81.58   -17.53      83.74   25.81       92.75
        SHA512      97.98   88.61       97.91   92.92       94.74
        AES     -12.85  30.10       35.62   67.23       24.54
        Deflate     47.73   -85.00      11.92   -167.55     32.38
        Bild        11.79   -228.30     9.89    -234.62     16.07
        Video       29.20   -73.89      62.39   -71.62      72.52
        DOM     -159.84 -752.46     -138.10 -1734.92        -91.05
        }mytableBaseA
    begin{axis}[
        axis line style={draw=none},% hide lines
        tick style={draw=none},% hide tick lines
        xmax = 160,
        xmin = -220,
        xbar, % bar chart
        y dir=reverse,%reverse y data
        y = 18mm,
        bar width = 2mm,
        /pgf/number format/.cd,%change context to number format
        use comma,%use comma instead of point
        1000 sep={.},%use point instead of comma
        fixed,
        ytick = data,% x-labels = x-column
        extra x ticks = {0},% tick line at position
        extra x tick labels = {},
        extra x tick style = {grid = major},% add grid line for x tick
        enlarge y limits = {abs = 10mm}, % space between border and outer bars origin
        symbolic y coords = {Base64, Sort, SHA256, SHA512, AES, Deflate, Bild, Video, DOM},% Use as x values
        ymajorgrids = true,
        y grid style={% workaround for bar groups background
            line width = 50pt,
            draw = black!3,
        },
        restrict x to domain*=-150:150,
        visualization depends on=rawxasrawx, % Save the unclipped values
        nodes near coords={%
            pgfmathprintnumber[fixed,fixed zerofill,precision=0,print sign]{rawx}~%
        },
        legend pos = outer north east,
        legend cell align={left},
        reverse legend,
    ]
        addplot[draw=none, fill=MediumTurquoise!50, area legend] table[x=firefoxpc-go, y=x] {mytableBaseA};
        addplot[draw=none, fill=MediumTurquoise, area legend] table[x=chromepc-go, y=x] {mytableBaseA};
        addplot[draw=none, fill=black!33, area legend] table[x=chromemobile-rust, y=x] {mytableBaseA};
        addplot[draw=none, fill=black!66, area legend] table[x=firefoxpc-rust, y=x] {mytableBaseA};
        addplot[draw=none, fill=black, area legend] table[x=chromepc-rust, y=x] {mytableBaseA};
        legend{FirefoxPC Go, ChromePC Go, ChromeMobile Rust, FirefoxPC Rust, ChromePC Rust}
        end{axis}
    end{tikzpicture}

end{document}