Fix race and remove unused features in cryptotoken extension

chrome/browser/resources/cryptotoken/gnubby.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 Low level usb cruft to talk gnubby.
  */
 
 'use strict';
 
@@ skipping 26 matching lines @@
   usbGnubby.gnubbies_ = gnubbies;
 };
 
 /**
  * @param {function(number, Array.<llGnubbyDeviceId>)} cb Called back with the
  *     result of enumerating.
  */
 usbGnubby.prototype.enumerate = function(cb) {
   if (!cb) cb = usbGnubby.defaultCallback;
   if (this.closed) {
-    cb(-llGnubby.GONE);
+    cb(-llGnubby.NODEVICE);
     return;
   }
   if (!usbGnubby.gnubbies_) {
     cb(-llGnubby.NODEVICE);
     return;
   }
 
   usbGnubby.gnubbies_.enumerate(cb);
 };
 
 /**
  * Opens the gnubby with the given index, or the first found gnubby if no
  * index is specified.
- * @param {llGnubbyDeviceId|undefined} opt_which The device to open.
+ * @param {llGnubbyDeviceId} which The device to open. If null, the first
+ *     gnubby found is opened.
  * @param {function(number)|undefined} opt_cb Called with result of opening the
  *     gnubby.
  */
-usbGnubby.prototype.open = function(opt_which, opt_cb) {
+usbGnubby.prototype.open = function(which, opt_cb) {
   var cb = opt_cb ? opt_cb : usbGnubby.defaultCallback;
   if (this.closed) {
-    cb(-llGnubby.GONE);
+    cb(-llGnubby.NODEVICE);
     return;
   }
   this.closingWhenIdle = false;
 
   if (document.location.href.indexOf('_generated_') == -1) {
     // Not background page.
     // Pick more random cid to tell things apart on the usb bus.
     var rnd = UTIL_getRandom(2);
     this.cid ^= (rnd[0] << 16) | (rnd[1] << 8);
   }
 
   var self = this;
-  function addSelfAsClient(which) {
+
+  function setCid(which) {
     self.cid &= 0x00ffffff;
     self.cid |= ((which.device + 1) << 24);  // For debugging.
+  }
 
+  var enumerateRetriesRemaining = 3;
+  function enumerated(rc, devs) {
+    if (!devs.length)
+      rc = -llGnubby.NODEVICE;
+    if (rc) {
+      cb(rc);
+      return;
+    }
+    which = devs[0];
+    setCid(which);
     usbGnubby.gnubbies_.addClient(which, self, function(rc, device) {
+      if (rc == -llGnubby.NODEVICE && enumerateRetriesRemaining-- > 0) {
+        // We were trying to open the first device, but now it's not there?
+        // Do over.
+        usbGnubby.gnubbies_.enumerate(enumerated);
+        return;
+      }
       self.dev = device;
       cb(rc);
     });
   }
 
-  if (!usbGnubby.gnubbies_) {
-    cb(-llGnubby.NODEVICE);
-    return;
-  }
-  if (opt_which) {
-    addSelfAsClient(opt_which);
+  if (which) {
+    setCid(which);
+    usbGnubby.gnubbies_.addClient(which, self, function(rc, device) {
+      self.dev = device;
+      cb(rc);
+    });
   } else {
-    usbGnubby.gnubbies_.enumerate(function(rc, devs) {
-      if (rc || !devs.length) {
-        cb(-llGnubby.NODEVICE);
-        return;
-      }
-      addSelfAsClient(devs[0]);
-    });
+    usbGnubby.gnubbies_.enumerate(enumerated);
   }
 };
 
 /**
  * @return {boolean} Whether this gnubby has any command outstanding.
  * @private
  */
 usbGnubby.prototype.inUse_ = function() {
   return this.commandPending;
 };
@@ skipping 95 matching lines @@
 };
 
 /** Poll from rxframes[].
  * @param {number} cmd Command
  * @param {number} timeout timeout in seconds.
  * @param {?function(...)} cb Callback
  * @private
  */
 usbGnubby.prototype.read_ = function(cmd, timeout, cb) {
   if (this.closed) { cb(-llGnubby.GONE); return; }
-  if (!this.dev) { cb(-llGnubby.NODEVICE); return; }
+  if (!this.dev) { cb(-llGnubby.GONE); return; }
 
   var tid = null;  // timeout timer id.
   var callback = cb;
   var self = this;
 
   var msg = null;
   var seqno = 0;
   var count = 0;
 
   /**
@@ skipping 198 matching lines @@
       busyWait.clearTimeout();
       cb(rc, rc_data);
     }
   }
 
   retryBusy(-llGnubby.BUSY, undefined);  // Start work.
 };
 
 /** Default callback for commands. Simply logs to console.
  * @param {number} rc Result status code
- * @param {*} data Result data
+ * @param {(ArrayBuffer|Uint8Array|Array.<number>|null)} data Result data
  */
 usbGnubby.defaultCallback = function(rc, data) {
   var msg = 'defaultCallback(' + rc;
   if (data) {
     if (typeof data == 'string') msg += ', ' + data;
     else msg += ', ' + UTIL_BytesToHex(new Uint8Array(data));
   }
   msg += ')';
   console.log(UTIL_fmt(msg));
 };
@@ skipping 222 matching lines @@
       }
     }
     // Warn on errors other than waiting for touch, wrong data, and
     // unrecognized command.
     if (rc != 0x6985 && rc != 0x6a80 && rc != 0x6d00) {
       console.warn(UTIL_fmt('apduReply_ fail: ' + rc.toString(16)));
     }
     cb(rc);
   });
 };