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

content/renderer/media/media_stream_video_capturer_source.cc

Index: content/renderer/media/media_stream_video_capturer_source.cc
diff --git a/content/renderer/media/media_stream_video_capturer_source.cc b/content/renderer/media/media_stream_video_capturer_source.cc
index d5e7f40efbec311b20e5021d0c8d8ec45f9226a7..d5114078882902b25c1be619342938b9fcac3bfc 100644
--- a/content/renderer/media/media_stream_video_capturer_source.cc
+++ b/content/renderer/media/media_stream_video_capturer_source.cc
@@ -182,14 +182,13 @@ void SetPowerLineFrequencyParamFromConstraints(
     const blink::WebMediaConstraints& constraints,
     media::VideoCaptureParams* params) {
   int freq;
-  params->power_line_frequency = media::PowerLineFrequency::FREQUENCY_DEFAULT;
   if (!GetOptionalConstraintValueAsInteger(constraints, kPowerLineFrequency,
                                            &freq)) {
     return;
   }
-  if (freq == static_cast<int>(media::PowerLineFrequency::FREQUENCY_50HZ))
+  if (freq == media::PowerLineFrequency::FREQUENCY_50HZ)
     params->power_line_frequency = media::PowerLineFrequency::FREQUENCY_50HZ;
-  else if (freq == static_cast<int>(media::PowerLineFrequency::FREQUENCY_60HZ))
+  else if (freq == media::PowerLineFrequency::FREQUENCY_60HZ)
     params->power_line_frequency = media::PowerLineFrequency::FREQUENCY_60HZ;
 }