keyboard shortcut is driving me crazy, how do I get rid of it? I use the keyboard shortcut CommandOptionL to lock my machine. For the most part this works, but not if Chrome is in focus. In Chrome, when I use that combination, it opens the "Downloads" page in a tab. I have tried everything I can think of to prevent this.

There is a menu item for "Downloads": Window -> Downloads. I have used the  System Preferences -> Keyboard -> Shortcuts -> App Shortcuts to attempt to set it to something else, but it doesn't seem to matter, I can add a new shortcut for Downloads, but no matter what I do CommandOptionL still opens Downloads. The only difference is the shortcut I configure highlights "Window" in the menu bar momentarily, while CommandOptionL does not. Although it does highlight if I set the shortcut to CommandOptionL.

I have even gone so far as to set defaults write com.google.Chrome NSUserKeyEquivalents -dict-add 'Downloads' '\0'.

When I read:

defaults read com.google.Chrome NSUserKeyEquivalents
{
    Downloads = "";
}


and yet CommandOptionL still opens the Downloads page.

Global keyboard shortcuts in macOS  have always been frustrating, but it was possible to override each conflicting app, but this one is driving me crazy.

EDIT: I also went through the chrome extensions and no keyboard shortcut was set to CommandOptionL. I also tried disabling all extensions; it did not work.
There is already a system wide keyboard shortcut to lock your display. It's CommandControlQ for High Sierra and higher and ControlShift⏏ on other systems, to let your display go to sleep (which is effectively the same when password protected). 

With this keyboard shortcuts in mind you can be sure, that they don't interfere with any application.

Note that on newer MacsBook Pros with Touch ID only the first keyboard shortcut works.