Add channel_count parameter back to AudioBuffer creation methods.

media/filters/audio_renderer_impl_unittest.cc

Index: media/filters/audio_renderer_impl_unittest.cc
diff --git a/media/filters/audio_renderer_impl_unittest.cc b/media/filters/audio_renderer_impl_unittest.cc
index c4fb6acef37d2467ebb1c3f45cb86dce669fc9f3..7cccdfcbbf3629f5d68b1b247c21b8d5ba5b0a1b 100644
--- a/media/filters/audio_renderer_impl_unittest.cc
+++ b/media/filters/audio_renderer_impl_unittest.cc
@@ -34,6 +34,7 @@ namespace media {
 static AudioCodec kCodec = kCodecVorbis;
 static SampleFormat kSampleFormat = kSampleFormatPlanarF32;
 static ChannelLayout kChannelLayout = CHANNEL_LAYOUT_STEREO;
+static int kChannelCount = 2;
 static int kChannels = ChannelLayoutToChannelCount(kChannelLayout);
 static int kSamplesPerSecond = 44100;
 
@@ -297,6 +298,7 @@ class AudioRendererImplTest : public ::testing::Test {
     scoped_refptr<AudioBuffer> buffer =
         MakeAudioBuffer<float>(kSampleFormat,
                                kChannelLayout,
+                               kChannelCount,
                                kSamplesPerSecond,
                                kPlayingAudio,
                                0.0f,