Reland: Add code to deal with serial device disconnection detection on Windows

base/win/scoped_device_info_object.h

+// Copyright 2015 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.
+
+#ifndef BASE_WIN_SCOPED_DEVICE_INFO_OBJECT_H_
+#define BASE_WIN_SCOPED_DEVICE_INFO_OBJECT_H_
+
+#include <windows.h>
+#include <setupapi.h>
+
+namespace base {
+namespace win {
+
+// Wrapper around an SP_DEVINFO_DATA that initializes it properly and
+// automatically deletes it.
+class ScopedDeviceInfo {
+ public:
+  ScopedDeviceInfo() {
+    memset(&dev_info_data_, 0, sizeof(dev_info_data_));
+    dev_info_data_.cbSize = sizeof(dev_info_data_);
+  }
+
+  ~ScopedDeviceInfo() {
+    if (dev_info_set_ != INVALID_HANDLE_VALUE) {
+      SetupDiDeleteDeviceInfo(dev_info_set_, &dev_info_data_);
+    }
+  }
+
+  // Once the SP_DEVINFO_DATA has been populated it must be freed using the
+  // HDEVINFO it was created from.
+  void set_valid(HDEVINFO dev_info_set) {
+    DCHECK(dev_info_set_ == INVALID_HANDLE_VALUE);

[Lei Zhang, 2015/11/13 01:38:25]

DCHECK_EQ / DCHECK_NE

+    DCHECK(dev_info_set != INVALID_HANDLE_VALUE);
+    dev_info_set_ = dev_info_set;
+  }
+
+  PSP_DEVINFO_DATA get() { return &dev_info_data_; }
+
+ private:
+  HDEVINFO dev_info_set_ = INVALID_HANDLE_VALUE;
+  SP_DEVINFO_DATA dev_info_data_;
+};

[Lei Zhang, 2015/11/13 01:38:25]

DISALLOW_COPY_AND_ASSIGN?

+
+}  // namespace win
+}  // namespace base
+
+#endif  // BASE_WIN_SCOPED_DEVICE_INFO_OBJECT_H_