ash: Add a heads-up display to track touch-point states and positions.

ash/ash_switches.cc

Index: ash/ash_switches.cc
diff --git a/ash/ash_switches.cc b/ash/ash_switches.cc
index 0d25477edf30b6280f8fc35fa69a7323798bd098..1e525be19deca33c4a16da2c699ec6a2c3c0667a 100644
--- a/ash/ash_switches.cc
+++ b/ash/ash_switches.cc
@@ -10,6 +10,9 @@ namespace switches {
 // Enables the Oak tree viewer.
 const char kAshEnableOak[] = "ash-enable-oak";
 
+// Enables the heads-up display for tracking touch points.
+const char kAshTouchHud[] = "ash-touch-hud";
+
 // Use Google-style dialog box frames.
 const char kAuraGoogleDialogFrames[] = "aura-google-dialog-frames";