MD Settings: Convert all usages of .bind(this) to use ES6 arrow function.

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

Index: chrome/browser/resources/settings/device_page/layout_behavior.js
diff --git a/chrome/browser/resources/settings/device_page/layout_behavior.js b/chrome/browser/resources/settings/device_page/layout_behavior.js
index d1665050e38acb5f5f8c73d069c0a053850acb63..0d1219102c8f0556c09f1786613fbfa906243b17 100644
--- a/chrome/browser/resources/settings/device_page/layout_behavior.js
+++ b/chrome/browser/resources/settings/device_page/layout_behavior.js
@@ -293,7 +293,7 @@ var LayoutBehavior = {
    */
   findChildren_: function(parentId, recurse) {
     var children = [];
-    this.displayLayoutMap_.forEach(function(value, key) {
+    this.displayLayoutMap_.forEach((value, key) => {
       var childId = key;
       if (childId != parentId && value.parentId == parentId) {
         // Insert immediate children at the front of the array.
@@ -303,7 +303,7 @@ var LayoutBehavior = {
           children = children.concat(this.findChildren_(childId, true));
         }
       }
-    }.bind(this));
+    });
     return children;
   },