Батник-патчер, убирающий это принудительное предупреждение:

1. Скопируйте код ниже и сохраните в любом текстовом редакторе как, например, DevWarningPatch.bat на рабочем столе

2. Закройте хром вручную, чтобы не потерять незаконченное письмо, например, батник сам завершит оставшиеся спрятанные процессы хрома принудительно.

3. Нажмите правой кнопкой мыши на сохраненном файле и запустите его от имени администратора, чтобы пропатчить все установленные версии хрома (поиск осуществляется посредством реестра или в текущей папке).

Также можно просто перетянуть chrome.dll из папки портабельного хрома на иконку батника.

<# :
@echo off
copy/b "%~f0" "%temp%\%~n0.ps1" >nul
powershell -Version 2 -ExecutionPolicy bypass -noprofile "%temp%\%~n0.ps1" "%cd% " "%~1"
del "%temp%\%~n0.ps1"
pause
exit /b
#>
param([string]$cwd='.', [string]$dll)

function main {
    "Chrome 'developer mode extensions' warning disabler v1.0.10.20170114`n"
    $pathsDone = @{}
    if ($dll -and (gi -literal $dll)) {
        doPatch "DRAG'n'DROPPED" ((gi -literal $dll).directoryName + '\')
        exit
    }
    doPatch CURRENT ((gi -literal $cwd).fullName + '\')
    ('HKLM', 'HKCU') | %{ $hive = $_
        ('', '\Wow6432Node') | %{
            $key = "${hive}:\SOFTWARE$_\Google\Update\Clients"
            gci -ea silentlycontinue $key -r | gp | ?{ $_.CommandLine } | %{
                $path = $_.CommandLine -replace '"(.+?\\\d+\.\d+\.\d+\.\d+\\).+', '$1'
                doPatch REGISTRY $path
            }
        }
    }
}

function doPatch([string]$pathLabel, [string]$path) {
    if ($pathsDone[$path.toLower()]) { return }

    $dll = $path + "chrome.dll"
    if (!(test-path -literal $dll)) {
        return
    }
    "======================="
    "$pathLabel PATH $((gi -literal $dll).DirectoryName)"

    "`tREADING Chrome.dll..."
    $bytes = [IO.File]::ReadAllBytes($dll)

    # process PE headers
    $BC = [BitConverter]
    $coff = $BC::ToUInt32($bytes,0x3C) + 4
    $is64 = $BC::ToUInt16($bytes,$coff) -eq 0x8664
    $opthdr = $coff+20
    $codesize = $BC::ToUInt32($bytes,$opthdr+4)
    $imagebase32 = $BC::ToUInt32($bytes,$opthdr+28)

    # patch the flag in data section
    $data = $BC::ToString($bytes,$codesize)
    $flag = "ExtensionDeveloperModeWarning"
    $stroffs = $data.IndexOf($BC::ToString($flag[1..99]))/3 - 1
    if ($stroffs -lt 0) {
        write-host -f red "`t$flag not found"
        return
    }
    $stroffs += $codesize
    if ($bytes[$stroffs] -eq 0) {
        write-host -f darkgreen "`tALREADY PATCHED"
        return
    }

    $exe = join-path (split-path $path) chrome.exe
    $EA = $ErrorActionPreference
    $ErrorActionPreference = 'silentlyContinue'
    while ((get-process chrome -module | ?{ $_.FileName -eq $exe })) {
        forEach ($timeout in 15..0) {
            write-host -n -b yellow -f black `
                "`rChrome is running and will be terminated in $timeout sec. "
            write-host -n -b yellow -f darkyellow "Press ENTER to do it now. "
            if ([console]::KeyAvailable) {
                $key = $Host.UI.RawUI.ReadKey("AllowCtrlC,IncludeKeyDown,NoEcho")
                if ($key.virtualKeyCode -eq 13) { break }
                if ($key.virtualKeyCode -eq 27) { write-host; exit }
            }
            sleep 1
        }
        write-host
        get-process chrome | ?{
            $_.MainWindowHandle.toInt64() -and ($_ | gps -file).FileName -eq $exe
        } | %{
            "`tTrying to exit gracefully..."
            if ($_.CloseMainWindow()) {
                sleep 1
            }
        }
        $killLabelShown = 0
        get-process chrome | ?{
            ($_ | gps -file | select -expand FileName) -eq $exe
        } | %{
            if (!$killLabelShown++) {
                "`tTerminating background chrome processes..."
            }
            stop-process $_ -force
        }
        sleep -milliseconds 200
    }
    $ErrorActionPreference = $EA

    $bytes[$stroffs] = 0
    "`tPATCHED $flag flag"

    # patch the channel restriction code for stable/beta
    $code = $BC::ToString($bytes,0,$codesize)
    $rxChannel = '83-F8-(?:03-7D|02-7F)'
    # old code: cmp eax,3; jge ...
    # new code: cmp eax,2; jg ...
    $chanpos = 0
    try {
        if ($is64) {
            $pos = 0
            $rx = [regex]"$rxChannel-.{1,100}-48-8D"
            do {
                $m = $rx.match($code,$pos)
                if (!$m.success) { break }
                $chanpos = $m.index/3 + 2
                $pos = $m.index + $m.length + 1
                $offs = $BC::ToUInt32($bytes,$pos/3+1)
                $diff = $pos/3+5+$offs - $stroffs
            } until ($diff -ge 0 -and $diff -le 4096 -and $diff % 256 -eq 0)
            if (!$m.success) {
                $rx = [regex]"84-C0.{18,48}($rxChannel)-.{30,60}84-C0"
                $m = $rx.matches($code)
                if ($m.count -ne 1) { throw }
                $chanpos = $m[0].groups[1].index/3 + 2
            }
        } else {
            $flagOffs = [uint32]$stroffs + [uint32]$imagebase32
            $flagOffsStr = $BC::ToString($BC::GetBytes($flagOffs))
            $variants = "(?<channel>$rxChannel-.{1,100})-68-(?<flag>`$1-.{6}`$2)",
                    "68-(?<flag>`$1-.{6}`$2).{300,500}E8.{12,32}(?<channel>$rxChannel)",
                    "E8.{12,32}(?<channel>$rxChannel).{300,500}68-(?<flag>`$1-.{6}`$2)"
            forEach ($variant in $variants) {
                $pattern = $flagOffsStr -replace '^(..)-.{6}(..)', $variant
                "`tLooking for $($pattern -replace '\?<.+?>', '')..."
                $minDiff = 65536
                foreach ($m in [regex]::matches($code, $pattern)) {
                    $maybeFlagOffs = $BC::toUInt32($bytes, $m.groups['flag'].index/3)
                    $diff = [Math]::abs($maybeFlagOffs - $flagOffs)
                    if ($diff % 256 -eq 0 -and $diff -lt $minDiff) {
                        $minDiff = $diff
                        $chanpos = $m.groups['channel'].index/3 + 2
                    }
                }
            }
            if (!$chanpos) { throw }
        }
    } catch {
        write-host -f red "`tUnable to find the channel code, try updating me"
        write-host -f red "`thttp://stackoverflow.com/a/30361260"
        return
    }
    $bytes[$chanpos] = 9
    "`tPATCHED Chrome release channel restriction"

    "`tWriting to a temporary dll..."
    [IO.File]::WriteAllBytes("$dll.new",$bytes)

    "`tBacking up the original dll..."
    move -literal $dll "$dll.bak" -force

    "`tRenaming the temporary dll as the original dll..."
    move -literal "$dll.new" $dll -force

    $pathsDone[$path.toLower()] = $true
    write-host -f green "`tDONE.`n"
    [GC]::Collect()
}

main