Refactoring: Use enum for RtpPayloadType.

chrome/renderer/extensions/cast_streaming_native_handler.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/extensions/cast_streaming_native_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 78 matching lines @@
   if (!base::HexStringToBytes(input, &bytes))
     return false;
   output->assign(reinterpret_cast<const char*>(&bytes[0]), bytes.size());
   return true;
 }
 }  // namespace
 
 bool ToCastRtpPayloadParamsOrThrow(v8::Isolate* isolate,
                                    const RtpPayloadParams& ext_params,
                                    CastRtpPayloadParams* cast_params) {
-  cast_params->payload_type = ext_params.payload_type;
+  DCHECK_GE(ext_params.payload_type, media::cast::RTP_PAYLOAD_AUDIO_OPUS);

[miu, 2016/06/20 21:00:27]

The process shouldn't crash on invalid inputs. Instead, the method should return
false.

Suggest you add a RtpPlayloadType::FIRST and LAST to the enum, then just test
the user's input with:

  if (ext_params.payload_type < FIRST || > LAST) {
    isolate->ThrowException(v8::Exception::Error(
        v8::String::NewFromUtf8(isolate, kInvalid...)));
    return false;
  }
  cast_params->payload_type = static_cast<...>(...);

[xjz, 2016/06/21 17:24:31]

Ignored |ext_params.payload_type| and set the |cast_params->payload_type|
according to |codec_name| instead.

+  DCHECK_LE(ext_params.payload_type, media::cast::RTP_PAYLOAD_VIDEO_LAST);
+  cast_params->payload_type =
+      static_cast<media::cast::RtpPayloadType>(ext_params.payload_type);
+
   cast_params->max_latency_ms = ext_params.max_latency;
   cast_params->min_latency_ms =
       ext_params.min_latency ? *ext_params.min_latency : ext_params.max_latency;
   cast_params->animated_latency_ms = ext_params.animated_latency
                                          ? *ext_params.animated_latency
                                          : ext_params.max_latency;
   cast_params->codec_name = ext_params.codec_name;
   cast_params->ssrc = ext_params.ssrc;
   cast_params->feedback_ssrc = ext_params.feedback_ssrc;
   cast_params->clock_rate = ext_params.clock_rate ? *ext_params.clock_rate : 0;
@@ skipping 559 matching lines @@
   config->rtp_max_delay_ms = params->max_latency;
   if (config->rtp_max_delay_ms < 0 || config->rtp_max_delay_ms > 1000) {
     isolate->ThrowException(v8::Exception::TypeError(
         v8::String::NewFromUtf8(isolate, kInvalidLatency)));
     return false;
   }
   config->channels = 2;
   if (params->codec_name == "OPUS") {
     config->codec = media::cast::CODEC_AUDIO_OPUS;
     config->rtp_timebase = 48000;
-    config->rtp_payload_type = media::cast::kDefaultRtpAudioPayloadType;
+    config->rtp_payload_type = media::cast::RTP_PAYLOAD_AUDIO_OPUS;
   } else if (params->codec_name == "PCM16") {
     config->codec = media::cast::CODEC_AUDIO_PCM16;
     config->rtp_timebase = 48000;
-    config->rtp_payload_type = media::cast::kDefaultRtpAudioPayloadType;
+    config->rtp_payload_type = media::cast::RTP_PAYLOAD_AUDIO_PCM16;
   } else if (params->codec_name == "AAC") {
     config->codec = media::cast::CODEC_AUDIO_AAC;
     config->rtp_timebase = 48000;
-    config->rtp_payload_type = media::cast::kDefaultRtpAudioPayloadType;
+    config->rtp_payload_type = media::cast::RTP_PAYLOAD_AUDIO_AAC;
   } else if (params->codec_name == "VP8") {
     config->codec = media::cast::CODEC_VIDEO_VP8;
     config->rtp_timebase = 90000;
-    config->rtp_payload_type = media::cast::kDefaultRtpVideoPayloadType;
+    config->rtp_payload_type = media::cast::RTP_PAYLOAD_VIDEO_VP8;
   } else if (params->codec_name == "H264") {
     config->codec = media::cast::CODEC_VIDEO_H264;
     config->rtp_timebase = 90000;
-    config->rtp_payload_type = media::cast::kDefaultRtpVideoPayloadType;
+    config->rtp_payload_type = media::cast::RTP_PAYLOAD_VIDEO_H264;
   }
   if (params->rtp_timebase) {
     config->rtp_timebase = *params->rtp_timebase;
     if (config->rtp_timebase < 1000 || config->rtp_timebase > 1000000) {
       isolate->ThrowException(v8::Exception::TypeError(
           v8::String::NewFromUtf8(isolate, kInvalidRtpTimebase)));
       return false;
     }
   }
   if (params->aes_key &&
@@ skipping 171 matching lines @@
     LOG(ERROR) << "Failed to add Cast audio track to media stream.";
   }
   if (!content::AddVideoTrackToMediaStream(std::move(video), true,  // is_remote
                                            true,  // is_readonly
                                            &web_stream)) {
     LOG(ERROR) << "Failed to add Cast video track to media stream.";
   }
 }
 
 }  // namespace extensions