Remove --echo-ext-path flag

chromeos/chromeos_switches.cc

Index: chromeos/chromeos_switches.cc
diff --git a/chromeos/chromeos_switches.cc b/chromeos/chromeos_switches.cc
index 83690723a5013fe75425b6961c70621fd3e15b32..f252742d9fa3ad25b7f72a65b3249cf99f1bdaf6 100644
--- a/chromeos/chromeos_switches.cc
+++ b/chromeos/chromeos_switches.cc
@@ -57,10 +57,6 @@ const char kDisableVolumeAdjustSound[] = "disable-volume-adjust-sound";
 const char kDisableNetworkPortalNotification[] =
     "disable-network-portal-notification";
 
-// Enables overriding the path for the default echo component extension.
-// Useful for testing.
-const char kEchoExtensionPath[]             = "echo-ext-path";
-
 // Enables switching between different cellular carriers from the UI.
 const char kEnableCarrierSwitching[]        = "enable-carrier-switching";