Adding "rtp_timebase" variable in lieu of "frequency" for FrameReceiverConfig structure.

media/cast/test/receiver.cc

Index: media/cast/test/receiver.cc
diff --git a/media/cast/test/receiver.cc b/media/cast/test/receiver.cc
index e930034c377999f9aeccb0c7e868cc43576dde1a..4fd265038409ed634359d3158bc523b7d9c3300a 100644
--- a/media/cast/test/receiver.cc
+++ b/media/cast/test/receiver.cc
@@ -152,10 +152,10 @@ FrameReceiverConfig GetVideoReceiverConfig() {
 }
 
 AudioParameters ToAudioParameters(const FrameReceiverConfig& config) {
-  const int samples_in_10ms = config.frequency / 100;
+  const int samples_in_10ms = config.rtp_timebase / 100;
   return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
                          GuessChannelLayout(config.channels),
-                         config.frequency, 32, samples_in_10ms);
+                         config.rtp_timebase, 32, samples_in_10ms);
 }
 
 // An InProcessReceiver that renders video frames to a LinuxOutputWindow and