Cast: Prefer VP8 over H.264 for hardware encoder

chrome/renderer/media/cast_rtp_stream.cc

Index: chrome/renderer/media/cast_rtp_stream.cc
diff --git a/chrome/renderer/media/cast_rtp_stream.cc b/chrome/renderer/media/cast_rtp_stream.cc
index 7c40523c302e21a5d7856d653839a2e3b91cd9f3..bbe675a076e57d4ea628f90d325df0a6d99e4117 100644
--- a/chrome/renderer/media/cast_rtp_stream.cc
+++ b/chrome/renderer/media/cast_rtp_stream.cc
@@ -151,9 +151,18 @@ std::vector<CastRtpParams> SupportedAudioParams() {
 
 std::vector<CastRtpParams> SupportedVideoParams() {
   std::vector<CastRtpParams> supported_params;
+
+  // Prefer VP8 over H.264 for hardware encoder.
+  if (IsHardwareVP8EncodingSupported())
+    supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
   if (IsHardwareH264EncodingSupported())
     supported_params.push_back(CastRtpParams(DefaultH264Payload()));
-  supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
+
+  // Propose the default software VP8 encoder, if no hardware encoders are
+  // available.
+  if (supported_params.empty())
+    supported_params.push_back(CastRtpParams(DefaultVp8Payload()));
+
   return supported_params;
 }