MD Settings: Pointers: Avoid setting mouse swap pref while mouse pressed

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * 'settings-pointers' is the settings subpage with mouse and touchpad settings.
  */
 Polymer({
   is: 'settings-pointers',
@@ skipping 14 matching lines @@
      * @const {!Array<number>}
      * @private
      */
     sensitivityValues_: {
       type: Array,
       value: [1, 2, 3, 4, 5],
       readOnly: true,
     },
   },
 
+  // Used to correctly identify when the mouse button has been released.
+  // crbug.com/686949.
+  receivedMouseSwapButtonsDown_: false,
+
   /**
    * Prevents the link from activating its parent paper-radio-button.
    * @param {!Event} e
    * @private
    */
   onLearnMoreLinkActivated_: function(e) {
     settings.DevicePageBrowserProxyImpl.getInstance().handleLinkEvent(e);
   },
 
   /**
    * Mouse and touchpad sections are only subsections if they are both present.
    * @param {boolean} hasMouse
    * @param {boolean} hasTouchpad
    * @return {string}
+   * @private
    */
   getSubsectionClass_: function(hasMouse, hasTouchpad) {
     return hasMouse && hasTouchpad ? 'subsection' : '';
   },
+
+  /** @private */
+  onMouseSwapButtonsDown_: function() {
+    this.receivedMouseSwapButtonsDown_ = true;
+  },
+
+  /** @private */
+  onMouseSwapButtonsUp_: function() {
+    this.receivedMouseSwapButtonsDown_ = false;
+    /** @type {!SettingsToggleButtonElement} */ (this.$.mouseSwapButton)
+        .sendPrefChange();
+  },
+
+  /** @private */
+  onMouseSwapButtonsChange_: function(event) {
+    if (!this.receivedMouseSwapButtonsDown_) {
+      /** @type {!SettingsToggleButtonElement} */ (this.$.mouseSwapButton)
+          .sendPrefChange();
+    }
+  },
 });