Remove navigator.vibrate without user gesture.

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index 1436426c834edee4716410d64a9562265bcf5ca5..895e085544e066836da263e74f2578446abe3194 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -226,6 +226,10 @@ const base::Feature kTokenBinding{"token-binding",
 const base::Feature kTouchpadAndWheelScrollLatching{
     "TouchpadAndWheelScrollLatching", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Controls whether vibrate requires user gesture.
+const base::Feature kVibrateRequiresUserGesture{
+    "VibrateRequiresUserGesture", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables VR UI.
 const base::Feature kVrShell{"VrShell", base::FEATURE_DISABLED_BY_DEFAULT};