Chrome Version: 69
OS: All desktop

In single-tab mode, the tab and window title are essentially the same thing (conceptually, there is no "tab", but just a single window containing a web page). So it doesn't make sense for there to be a separate tab context menu and window context menu.

If we're going to have single-tab mode that hides the visual of a tab, we should lean into it and 
pretend it isn't a tab as much as possible. The tab context menu should be combined into a single context menu for the window + its only tab.

Tab context menu items:

- New tab -- already in window context menu
- Reload -- combine into window context menu
- Duplicate -- not sure; weird since this "isn't a tab"
- Pin tab -- not sure; a bit weird but still useful
- Mute site -- combine into window context menu
- Close tab -- should be removed (since there's already "Close [window]")
- Close other tabs -- should be removed (doesn't make sense in this mode)
- Close tabs to the right -- should be removed (doesn't make sense in this mode)
- Reopen closed window -- already in window context menu (why is this on the tab context menu anyway?)
- Bookmark all tabs -- combine into window context menu, but rename to "Bookmark page"

For reference, the window context menu items:

- Minimize
- Restore
- New tab
- Reopen closed window
- Task manager
- Use system title bar and borders (Linux only)
- Close [window]

It seems the easiest way to go about this would be to conditionally add a few items to the window context menu in single tab mode (Reload, Mute site, Bookmark), and then make right-clicking the tab always open the window context menu in STM.

See also  Issue 848380 .