Fix race and remove unused features in cryptotoken extension

chrome/browser/resources/cryptotoken/llhidgnubby.js

 // Copyright 2014 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 Implements a low-level gnubby driver based on chrome.hid.
  */
 'use strict';
 
 /**
@@ skipping 22 matching lines @@
 /**
  * Namespace for the llHidGnubby implementation.
  * @const
  */
 llHidGnubby.NAMESPACE = 'hid';
 
 /** Destroys this low-level device instance. */
 llHidGnubby.prototype.destroy = function() {
   if (!this.dev) return;  // Already dead.
 
+  this.gnubbies_.removeOpenDevice(
+      {namespace: llHidGnubby.NAMESPACE, device: this.id});
   this.closing = true;
 
   console.log(UTIL_fmt('llHidGnubby.destroy()'));
 
   // Synthesize a close error frame to alert all clients,
   // some of which might be in read state.
   //
   // Use magic CID 0 to address all.
   this.publishFrame_(new Uint8Array([
         0, 0, 0, 0,  // broadcast CID
         llGnubby.CMD_ERROR,
         0, 1,  // length
         llGnubby.GONE]).buffer);
 
   // Set all clients to closed status and remove them.
   while (this.clients.length != 0) {
     var client = this.clients.shift();
     if (client) client.closed = true;
   }
 
   if (this.lockTID) {
     window.clearTimeout(this.lockTID);
     this.lockTID = null;
   }
 
   var dev = this.dev;
   this.dev = null;
 
-  var self = this;
-
-  function onClosed() {
+  chrome.hid.disconnect(dev.connectionId, function() {
     console.log(UTIL_fmt('Device ' + dev.handle + ' closed'));
-    self.gnubbies_.removeOpenDevice(
-        {namespace: llHidGnubby.NAMESPACE, device: self.id});
-  }
-
-  chrome.hid.disconnect(dev.connectionId, onClosed);
+  });
 };
 
 /**
  * Push frame to all clients.
  * @param {ArrayBuffer} f Data to push
  * @private
  */
 llHidGnubby.prototype.publishFrame_ = function(f) {
   var old = this.clients;
 
   var remaining = [];
   var changes = false;
   for (var i = 0; i < old.length; ++i) {
     var client = old[i];
     if (client.receivedFrame(f)) {
       // Client still alive; keep on list.
       remaining.push(client);
     } else {
       changes = true;
       console.log(UTIL_fmt(
           '[' + client.cid.toString(16) + '] left?'));
     }
   }
   if (changes) this.clients = remaining;
 };
 
 /**
- * @return {boolean} whether this device is open and ready to use.
- * @private
- */
-llHidGnubby.prototype.readyToUse_ = function() {
-  if (this.closing) return false;
-  if (!this.dev) return false;
-
-  return true;
-};
-
-/**
  * Register a client for this gnubby.
  * @param {*} who The client.
  */
 llHidGnubby.prototype.registerClient = function(who) {
   for (var i = 0; i < this.clients.length; ++i) {
     if (this.clients[i] === who) return;  // Already registered.
   }
   this.clients.push(who);
   if (this.clients.length == 1) {
     // First client? Kick off read loop.
@@ skipping 164 matching lines @@
           this.lockMillis);
     }
   }
 };
 
 /**
  * Queue command to be sent.
  * If queue was empty, initiate the write.
  * @param {number} cid The client's channel ID.
  * @param {number} cmd The command to send.
- * @param {ArrayBuffer} data Command arguments
+ * @param {ArrayBuffer|Uint8Array} data Command arguments
  */
 llHidGnubby.prototype.queueCommand = function(cid, cmd, data) {
   if (!this.dev) return;
   if (!this.checkLock_(cid, cmd)) return;
 
   var u8 = new Uint8Array(data);
   var f = new Uint8Array(64);
 
   llHidGnubby.setCid_(f, cid);
   f[4] = cmd;
@@ skipping 136 matching lines @@
  * @param {Gnubbies} gnubbies Gnubbies registry
  */
 llHidGnubby.register = function(gnubbies) {
   var HID_GNUBBY_IMPL = {
     enumerate: llHidGnubby.enumerate,
     deviceToDeviceId: llHidGnubby.deviceToDeviceId,
     open: llHidGnubby.open
   };
   gnubbies.registerNamespace(llHidGnubby.NAMESPACE, HID_GNUBBY_IMPL);
 };