Better mechanism to fade out the side bar when not on EmuScreen

UI/EmuScreen.cpp

@@ -197,7 +197,6 @@ EmuScreen::EmuScreen(const Path &filename)
 	// Usually, we don't want focus movement enabled on this screen, so disable on start.
 	// Only if you open chat or dev tools do we want it to start working.
 	UI::EnableFocusMovement(false);
-	g_OSD.SetShowSidebar(true);
 }
 
 bool EmuScreen::bootAllowStorage(const Path &filename) {
@@ -1480,6 +1479,8 @@ void EmuScreen::render() {
 	if (!thin3d)
 		return;  // shouldn't really happen but I've seen a suspicious stack trace..
 
+	g_OSD.NudgeSidebar();
+
 	if (invalid_) {
 		// Loading, or after shutdown?
 		if (loadingTextView_->GetVisibility() == UI::V_VISIBLE)