diff --git a/src/utils/resize-event.ts b/src/utils/resize-event.ts
deleted file mode 100644
index 9fa30aed96..0000000000
--- a/src/utils/resize-event.ts
+++ /dev/null
@@ -1,37 +0,0 @@
-import ResizeObserver from 'resize-observer-polyfill'
-import { NOOP } from '@vue/shared'
-const isServer = typeof window === 'undefined'
-
-// TODO: add hack prototype __resizeListeners__
-
-/* istanbul ignore next */
-const resizeHandler = function(entries: ResizeObserverEntry[]) {
-  for (const entry of entries) {
-    const listeners = entry.target.__resizeListeners__ || []
-    if (listeners.length) {
-      listeners.forEach(fn => {
-        fn()
-      })
-    }
-  }
-}
-
-/* istanbul ignore next */
-export const addResizeListener = function(element, fn) {
-  if (isServer) return
-  if (!element.__resizeListeners__) {
-    element.__resizeListeners__ = []
-    element.__ro__ = new ResizeObserver(NOOP)
-    element.__ro__.observe(element)
-  }
-  element.__resizeListeners__.push(fn)
-}
-
-/* istanbul ignore next */
-export const removeResizeListener = function(element, fn) {
-  if (!element || !element.__resizeListeners__) return
-  element.__resizeListeners__.splice(element.__resizeListeners__.indexOf(fn), 1)
-  if (!element.__resizeListeners__.length) {
-    element.__ro__.disconnect()
-  }
-}
diff --git a/src/utils/util.ts b/src/utils/util.ts
deleted file mode 100644
index 7a51142404..0000000000
--- a/src/utils/util.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-export const autoprefixer = function(style) {
-  if (typeof style !== 'object') return style
-  const rules = ['transform', 'transition', 'animation']
-  const prefixes = ['ms-', 'webkit-']
-  rules.forEach(rule => {
-    const value = style[rule]
-    if (rule && value) {
-      prefixes.forEach(prefix => {
-        style[prefix + rule] = value
-      })
-    }
-  })
-  return style
-}