Change the media::PowerLineFrequency from an enum class to a proper class

media/capture/video/win/video_capture_device_win.cc

Index: media/capture/video/win/video_capture_device_win.cc
diff --git a/media/capture/video/win/video_capture_device_win.cc b/media/capture/video/win/video_capture_device_win.cc
index 60e4fe8481fbdf993459803bf425eb6e5ddb0c08..b23fa6811f98893ee68b822c463e6892d4db9d64 100644
--- a/media/capture/video/win/video_capture_device_win.cc
+++ b/media/capture/video/win/video_capture_device_win.cc
@@ -538,9 +538,9 @@ void VideoCaptureDeviceWin::SetAntiFlickerInCaptureFilter(
     const VideoCaptureParams& params) {
   const int power_line_frequency = GetPowerLineFrequency(params);
   if (power_line_frequency !=
-          static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ) &&
+          media::PowerLineFrequency::FREQUENCY_50HZ &&
       power_line_frequency !=
-          static_cast<int>(media::PowerLineFrequency::FREQUENCY_60HZ)) {
+          media::PowerLineFrequency::FREQUENCY_60HZ) {
     return;
   }
   ScopedComPtr<IKsPropertySet> ks_propset;
@@ -557,7 +557,7 @@ void VideoCaptureDeviceWin::SetAntiFlickerInCaptureFilter(
     data.Property.Id = KSPROPERTY_VIDEOPROCAMP_POWERLINE_FREQUENCY;
     data.Property.Flags = KSPROPERTY_TYPE_SET;
     data.Value = (power_line_frequency ==
-                  static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ))
+                  media::PowerLineFrequency::FREQUENCY_50HZ)
                      ? 1
                      : 2;
     data.Flags = KSPROPERTY_VIDEOPROCAMP_FLAGS_MANUAL;