Refactor AudioParameters member setting.

media/base/channel_mixer_unittest.cc

Index: media/base/channel_mixer_unittest.cc
diff --git a/media/base/channel_mixer_unittest.cc b/media/base/channel_mixer_unittest.cc
index 89b4eeedc44397281c1b03fa466d008c1127bffc..1eb2616236c871c43cdf3775c7c4b927d52cf30f 100644
--- a/media/base/channel_mixer_unittest.cc
+++ b/media/base/channel_mixer_unittest.cc
@@ -104,26 +104,19 @@ TEST_P(ChannelMixerTest, Mixing) {
   ChannelLayout input_layout = GetParam().input_layout;
   int input_channels = GetParam().input_channels;
   scoped_ptr<AudioBus> input_bus = AudioBus::Create(input_channels, kFrames);
-  AudioParameters input_audio(AudioParameters::AUDIO_PCM_LINEAR,
-                              input_layout,
-                              input_layout == CHANNEL_LAYOUT_DISCRETE ?
-                                  input_channels :
-                                  ChannelLayoutToChannelCount(input_layout),
-                              AudioParameters::kAudioCDSampleRate, 16,
-                              kFrames,
-                              AudioParameters::NO_EFFECTS);
+  AudioParameters input_audio(AudioParameters::AUDIO_PCM_LINEAR, input_layout,
+                              AudioParameters::kAudioCDSampleRate, 16, kFrames);
+  if (input_layout == CHANNEL_LAYOUT_DISCRETE)
+    input_audio.set_channels_for_discrete(input_channels);
 
   ChannelLayout output_layout = GetParam().output_layout;
   int output_channels = GetParam().output_channels;
   scoped_ptr<AudioBus> output_bus = AudioBus::Create(output_channels, kFrames);
-  AudioParameters output_audio(AudioParameters::AUDIO_PCM_LINEAR,
-                               output_layout,
-                               output_layout == CHANNEL_LAYOUT_DISCRETE ?
-                                   output_channels :
-                                   ChannelLayoutToChannelCount(output_layout),
+  AudioParameters output_audio(AudioParameters::AUDIO_PCM_LINEAR, output_layout,
                                AudioParameters::kAudioCDSampleRate, 16,
-                               kFrames,
-                               AudioParameters::NO_EFFECTS);
+                               kFrames);
+  if (output_layout == CHANNEL_LAYOUT_DISCRETE)
+    output_audio.set_channels_for_discrete(output_channels);
 
   const float* channel_values = GetParam().channel_values;
   ASSERT_EQ(input_bus->channels(), GetParam().num_channel_values);