Linux: Dynamically load libudev.

device/udev_linux/udev_loader.cc

+// 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.
+
+#include "device/udev_linux/udev_loader.h"
+
+#include "base/logging.h"
+#include "device/udev_linux/udev0_loader.h"
+#include "device/udev_linux/udev1_loader.h"
+
+namespace device {
+
+namespace {
+
+UdevLoader* g_udev_loader = NULL;
+
+}  // namespace
+
+// static
+UdevLoader* UdevLoader::Get() {
+  if (g_udev_loader)
+    return g_udev_loader;
+
+  scoped_ptr<UdevLoader> udev_loader;
+  udev_loader.reset(new Udev1Loader);
+  if (udev_loader->Init()) {
+    g_udev_loader = udev_loader.release();
+    return g_udev_loader;
+  }
+
+  udev_loader.reset(new Udev0Loader);
+  if (udev_loader->Init()) {
+    g_udev_loader = udev_loader.release();
+    return g_udev_loader;
+  }
+  CHECK(false);
+  return NULL;
+}
+
+UdevLoader::~UdevLoader() {
+}
+
+}  // namespace device