Refactoring: Merge VideoSenderConfig and AudioSenderConfig.

media/cast/sender/vp8_encoder.h

Index: media/cast/sender/vp8_encoder.h
diff --git a/media/cast/sender/vp8_encoder.h b/media/cast/sender/vp8_encoder.h
index dd7d57c2da9012e875ae799d1cdf42f1f36ce24e..2ae87da8eab87749a1eb866757bfa2b1e57b2285 100644
--- a/media/cast/sender/vp8_encoder.h
+++ b/media/cast/sender/vp8_encoder.h
@@ -26,7 +26,7 @@ namespace cast {
 
 class Vp8Encoder : public SoftwareVideoEncoder {
  public:
-  explicit Vp8Encoder(const VideoSenderConfig& video_config);
+  explicit Vp8Encoder(const FrameSenderConfig& video_config);
 
   ~Vp8Encoder() final;
 
@@ -51,7 +51,7 @@ class Vp8Encoder : public SoftwareVideoEncoder {
   // |encoder_| instance.
   void ConfigureForNewFrameSize(const gfx::Size& frame_size);
 
-  const VideoSenderConfig cast_config_;
+  const FrameSenderConfig cast_config_;
 
   const double target_deadline_utilization_;