Add U2F device enumeration class

device/u2f/u2f_enumerate.cc

Index: device/u2f/u2f_enumerate.cc
diff --git a/device/u2f/u2f_enumerate.cc b/device/u2f/u2f_enumerate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a68bd611d5b882944c82e4188a67722b5a79ffd2
--- /dev/null
+++ b/device/u2f/u2f_enumerate.cc
@@ -0,0 +1,52 @@
+// Copyright 2017 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 "u2f_enumerate.h"
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "device/base/device_client.h"
+#include "u2f_hid_device.h"
+
+namespace device {
+
+U2fEnumerate::U2fEnumerate()
+    : hid_service_observer_(this), weak_factory_(this) {
+  filter_.SetUsagePage(0xf1d0);
+}
+
+U2fEnumerate::~U2fEnumerate() {}
+
+void U2fEnumerate::EnumerateU2fDevices(
+    U2fEnumerate::U2fEnumerateCallback enumerate_cb) {
+  HidService* hid_service = DeviceClient::Get()->GetHidService();
+  DCHECK(hid_service);
+  hid_service_observer_.Add(hid_service);
+  hid_service->GetDevices(base::Bind(&U2fEnumerate::OnHidEnumerationComplete,
+                                     weak_factory_.GetWeakPtr(),
+                                     base::Passed(&enumerate_cb)));
+}
+
+void U2fEnumerate::OnHidEnumerationComplete(
+    U2fEnumerate::U2fEnumerateCallback callback,
+    const std::vector<scoped_refptr<HidDeviceInfo>>& devices) {
+  std::list<std::unique_ptr<U2fDevice>> u2f_devices;
+  for (const scoped_refptr<HidDeviceInfo>& device_info : devices) {
+    if (filter_.Matches(device_info))
+      u2f_devices.push_back(base::MakeUnique<U2fHidDevice>(device_info));
+  }
+  std::move(callback).Run(std::move(u2f_devices));
+}
+
+void U2fEnumerate::OnDeviceAdded(scoped_refptr<HidDeviceInfo> device_info) {
+  if (device_added_cb_ && filter_.Matches(device_info))
+    device_added_cb_.Run(base::MakeUnique<U2fHidDevice>(device_info));
+}
+
+void U2fEnumerate::OnDeviceRemoved(scoped_refptr<HidDeviceInfo> device_info) {
+  if (device_removed_cb_ && filter_.Matches(device_info))
+    device_removed_cb_.Run(base::MakeUnique<U2fHidDevice>(device_info));
+}
+
+}  // namespace device