Add device path enumeration to the new Windows USB backend.

device/usb/BUILD.gn

Index: device/usb/BUILD.gn
diff --git a/device/usb/BUILD.gn b/device/usb/BUILD.gn
index 4e22715bd8cf9096769a65e974bfb0d7e3cc191d..9fb12359365781a48ac72764774741e5deccf3af 100644
--- a/device/usb/BUILD.gn
+++ b/device/usb/BUILD.gn
@@ -34,6 +34,8 @@ static_library("usb") {
     "usb_device_handle_android.h",
     "usb_device_linux.cc",
     "usb_device_linux.h",
+    "usb_device_win.cc",
+    "usb_device_win.h",
     "usb_endpoint_android.cc",
     "usb_endpoint_android.h",
     "usb_ids.cc",
@@ -89,6 +91,10 @@ static_library("usb") {
     deps += [ "//third_party/libusb" ]
   }
 
+  if (is_win) {
+    libs = [ "setupapi.lib" ]
+  }
+
   if (is_android || is_chromeos || is_linux) {
     sources += [
       "usb_device_handle_usbfs.cc",