Hooked up Opus CBR support when configured manually or through an SdpAudioFormat.

webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus_unittest.cc

Index: webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus_unittest.cc
diff --git a/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus_unittest.cc b/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus_unittest.cc
index 788d799a1191fd12b28cfd8ba7aab89edf4bb20b..76574d6432407f0ef30c6f98853a30fef0100379 100644
--- a/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus_unittest.cc
+++ b/webrtc/modules/audio_coding/codecs/opus/audio_encoder_opus_unittest.cc
@@ -583,6 +583,12 @@ TEST(AudioEncoderOpusTest, TestConfigFromParams) {
   config = CreateConfigWithParameters({{"usedtx", "1"}});
   EXPECT_TRUE(config.dtx_enabled);
 
+  config = CreateConfigWithParameters({{"cbr", "0"}});
+  EXPECT_FALSE(config.cbr_enabled);
+
+  config = CreateConfigWithParameters({{"cbr", "1"}});
+  EXPECT_TRUE(config.cbr_enabled);
+
   config = CreateConfigWithParameters({{"maxplaybackrate", "12345"}});
   EXPECT_EQ(12345, config.max_playback_rate_hz);
 
@@ -633,6 +639,9 @@ TEST(AudioEncoderOpusTest, TestConfigFromInvalidParams) {
   config = CreateConfigWithParameters({{"usedtx", "invalid"}});
   EXPECT_EQ(default_config.dtx_enabled, config.dtx_enabled);
 
+  config = CreateConfigWithParameters({{"cbr", "invalid"}});
+  EXPECT_EQ(default_config.dtx_enabled, config.dtx_enabled);
+
   config = CreateConfigWithParameters({{"maxplaybackrate", "0"}});
   EXPECT_EQ(default_config.max_playback_rate_hz, config.max_playback_rate_hz);