DuckDuckGo search box does not bring up keyboard input on ML

[jdm]

This may be a regression from #22871.

[asajeffrey]

Yeah, libsimpleservo ignores HideIME and ShowIME events:

servo/ports/libsimpleservo/api/src/lib.rs

Lines 571 to 574 in c475755

	EmbedderMsg::ShowIME(..) |
	EmbedderMsg::HideIME |
	EmbedderMsg::Panic(..) |
	EmbedderMsg::ReportProfile(..) => {},

I filed #23969.