ash/keyboard/README.md
The virtual keyboard can be enabled or disabled. When it is enabled, it shows and hides depending where the focus is.
Whether the virtual keyboard is enabled depends on a sequence of criteria that are listed in order below:
--enable-virtual-keyboard and --disable-virtual-keyboard command line switches (and their corresponding flags in about://flags) enables and disables the virtual keyboard.chrome.virtualKeyboardPrivate.setKeyboardState API.