Fix 'not all switch case are handled' warning in OSWindow.cpp Change-Id: Ib4d1e4b04c73e5eb5e0e4f6c56212e99723d2ce0 Reviewed-on: https://chromium-review.googlesource.com/269126 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Corentin Wallez <cwallez@chromium.org>