media: Add out-of-line copy ctors for complex classes.

media/cast/cast_config.cc

Index: media/cast/cast_config.cc
diff --git a/media/cast/cast_config.cc b/media/cast/cast_config.cc
index f3b1612b74f7c9b0e7b72a79ac0b3d49da522832..1a619fd0703985f49a2ac06d73765ae1a81fb717 100644
--- a/media/cast/cast_config.cc
+++ b/media/cast/cast_config.cc
@@ -58,6 +58,8 @@ VideoSenderConfig::VideoSenderConfig()
       codec(CODEC_VIDEO_VP8),
       number_of_encode_threads(1) {}
 
+VideoSenderConfig::VideoSenderConfig(const VideoSenderConfig& other) = default;
+
 VideoSenderConfig::~VideoSenderConfig() {}
 
 AudioSenderConfig::AudioSenderConfig()
@@ -72,6 +74,8 @@ AudioSenderConfig::AudioSenderConfig()
       bitrate(kDefaultAudioEncoderBitrate),
       codec(CODEC_AUDIO_OPUS) {}
 
+AudioSenderConfig::AudioSenderConfig(const AudioSenderConfig& other) = default;
+
 AudioSenderConfig::~AudioSenderConfig() {}
 
 FrameReceiverConfig::FrameReceiverConfig()
@@ -84,6 +88,9 @@ FrameReceiverConfig::FrameReceiverConfig()
       target_frame_rate(0),
       codec(CODEC_UNKNOWN) {}
 
+FrameReceiverConfig::FrameReceiverConfig(const FrameReceiverConfig& other) =
+    default;
+
 FrameReceiverConfig::~FrameReceiverConfig() {}
 
 }  // namespace cast