Extracted hardcoded constants from cast_rtp_stream.

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 1b9d2da7b055d32dfe99a87b7fd11399fa83e1c7..042d0fb943a659e077ac88d93ec0f1e1919e316c 100644
--- a/chrome/renderer/media/cast_rtp_stream.cc
+++ b/chrome/renderer/media/cast_rtp_stream.cc
@@ -26,6 +26,7 @@
 #include "media/base/audio_converter.h"
 #include "media/base/audio_fifo.h"
 #include "media/base/bind_to_current_loop.h"
+#include "media/base/limits.h"
 #include "media/base/video_frame.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/cast_defines.h"
@@ -181,7 +182,7 @@ bool ToAudioSenderConfig(const CastRtpParams& params,
   config->rtp_payload_type = params.payload.payload_type;
   config->use_external_encoder = false;
   config->frequency = params.payload.clock_rate;
-  if (config->frequency < 8000)
+  if (config->frequency < media::cast::kMinSampleRateForEncoding)

[mcasas, 2015/09/15 16:59:39]

If |kMinSampleRateForEncoding| is only used in this file
you should move it to here around l.43, so is not exported
-- less symbols for the linker etc.

[miu, 2015/09/15 22:05:22]

I disagree with this one.  IMO, the constant belongs in the cast_defines.h
header file since it pertains to all clients of the media/cast library.

Side note: We plan to re-do all the int constants as enums as part of a massive
clean-up bug we're about to start on, which would resolve the "extra linking"
problem.

     return false;
   config->channels = params.payload.channels;
   if (config->channels < 1)
@@ -222,7 +223,7 @@ bool ToVideoSenderConfig(const CastRtpParams& params,
   config->start_bitrate = config->min_bitrate;
   config->max_frame_rate = static_cast<int>(
       std::max(1.0, params.payload.max_frame_rate) + 0.5);
-  if (config->max_frame_rate > 120)
+  if (config->max_frame_rate > media::limits::kMaxFramesPerSecond)
     return false;
   if (params.payload.codec_name == kCodecNameVp8) {
     config->use_external_encoder = IsHardwareVP8EncodingSupported();