Remove the BackspaceGoesBack flag.

chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc

Index: chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
diff --git a/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc b/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
index ae29d008423206118d2530689833eca173ba9add..afdb917cabc119387b375ab696d66246e667ce56 100644
--- a/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/keyboard_overlay_ui.cc
@@ -316,9 +316,6 @@ content::WebUIDataSource* CreateKeyboardOverlayUIHTMLSource(Profile* profile) {
   display::DisplayManager* display_manager = shell->display_manager();
   source->AddBoolean("keyboardOverlayIsDisplayUIScalingEnabled",
                      display_manager->IsDisplayUIScalingEnabled());
-  source->AddBoolean(
-      "backspaceGoesBackFeatureEnabled",
-      base::FeatureList::IsEnabled(features::kBackspaceGoesBackFeature));
   source->SetJsonPath("strings.js");
   source->AddResourcePath("keyboard_overlay.js", IDR_KEYBOARD_OVERLAY_JS);
   source->SetDefaultResource(IDR_KEYBOARD_OVERLAY_HTML);