Fixes leaking transfer objects due to improper USB handle closure.

chrome/browser/extensions/api/usb/usb_api.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/extensions/api/usb/usb_api.h"
 
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 456 matching lines @@
                  base::Unretained(service),
                  vendor_id,
                  product_id,
                  interface_id,
                  base::Bind(&UsbFindDevicesFunction::OnEnumerationCompleted,
                             this)));
 }
 
 void UsbFindDevicesFunction::OnEnumerationCompleted(
     ScopedDeviceVector devices) {
-  for (size_t i = 0; i < devices->size(); ++i)
-    device_handles_.push_back(devices->at(i)->Open());
+  for (size_t i = 0; i < devices->size(); ++i) {
+    scoped_refptr<UsbDeviceHandle> device_handle =
+      devices->at(i)->Open();
+    if (device_handle)
+      device_handles_.push_back(device_handle);
+  }
 
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&UsbFindDevicesFunction::OnCompleted, this));
 }
 
 void UsbFindDevicesFunction::OnCompleted() {
   for (size_t i = 0; i < device_handles_.size(); ++i) {
     UsbDeviceHandle* const device_handle = device_handles_[i].get();
@@ skipping 553 matching lines @@
 }
 
 void UsbResetDeviceFunction::OnError() {
   RemoveUsbDeviceResource(parameters_->device.handle);
   SetError(kErrorResetDevice);
   SetResult(Value::CreateBooleanValue(false));
   AsyncWorkCompleted();
 }
 
 }  // namespace extensions