MD Settings: Eliminate use of ES6 for Chrome OS

chrome/browser/resources/settings/device_page/drag_behavior.js

Index: chrome/browser/resources/settings/device_page/drag_behavior.js
diff --git a/chrome/browser/resources/settings/device_page/drag_behavior.js b/chrome/browser/resources/settings/device_page/drag_behavior.js
index 8bec4daab1c8a496709928b88127478644ed5459..c08cf0ccc952d56c2e8d11cefe4b96d6be2c5db7 100644
--- a/chrome/browser/resources/settings/device_page/drag_behavior.js
+++ b/chrome/browser/resources/settings/device_page/drag_behavior.js
@@ -81,7 +81,7 @@ var DragBehavior = {
 
   /** @private */
   addListeners_: function() {
-    let container = this.container_;
+    var container = this.container_;
     if (!container || this.mouseDownListener_)
       return;
     this.mouseDownListener_ = this.onMouseDown_.bind(this);
@@ -103,7 +103,7 @@ var DragBehavior = {
 
   /** @private */
   removeListeners_: function() {
-    let container = this.container_;
+    var container = this.container_;
     if (!container || !this.mouseDownListener_)
       return;
     container.removeEventListener('mousedown', this.mouseDownListener_);