[Switch Access] Clean up unused code in switch_access_subpage.js

AX-Relnotes: N/A.
Bug: 1156494
Change-Id: I99fb4980235a9be55b5c5e8674d43f0c1326899a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2577734Reviewed-by: Jimmy Gong <jimmyxgong@chromium.org>
Commit-Queue: Jimmy Gong <jimmyxgong@chromium.org>
Auto-Submit: Josiah Krutz <josiahk@google.com>
Cr-Commit-Position: refs/heads/master@{#835083}

chrome/browser/resources/settings/chromeos/os_a11y_page/switch_access_subpage.js

@@ -13,19 +13,6 @@
  */
 const PREFIX = 'settings.a11y.switch_access.';
 
-/**
- * The ending of the setting name for all key code preferences.
- * @const
- */
-const KEY_CODE_SUFFIX = '.key_codes';
-
-/**
- * The ending of the setting name for all preferences referring to
- * Switch Access command settings.
- * @const
- */
-const COMMAND_SUFFIX = '.setting';
-
 /** @type {!Array<number>} */
 const AUTO_SCAN_SPEED_RANGE_MS = [
   700,  800,  900,  1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800,
@@ -42,21 +29,6 @@ function ticksWithLabelsInSec(ticksInMs) {
   return ticksInMs.map(x => ({label: `${x / 1000}`, value: x}));
 }
 
-/**
- * @param {!Array} array
- * @param {*} value
- * @return {!Array}
- */
-function removeElementWithValue(array, value) {
-  for (let i = 0; i < array.length; i++) {
-    if (array[i].value === value) {
-      array.splice(i, 1);
-      return array;
-    }
-  }
-  return array;
-}
-
 Polymer({
   is: 'settings-switch-access-subpage',
 
@@ -264,18 +236,6 @@ Polymer({
     }
   },
 
-  /**
-   * @return {string}
-   * @private
-   */
-  currentSpeed_() {
-    const speed = this.getPref(PREFIX + 'auto_scan.speed_ms').value;
-    if (typeof speed !== 'number') {
-      return '';
-    }
-    return this.scanSpeedStringInSec_(speed);
-  },
-
   /**
    * @return {boolean} Whether to show settings for auto-scan within the
    *     keyboard.