Fix a few small nits in NetEq4

TEST=try bots

Review URL: https://webrtc-codereview.appspot.com/1061010

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3431 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/neteq4/neteq_impl.h b/webrtc/modules/audio_coding/neteq4/neteq_impl.h
index 18169dc..eff6115 100644
--- a/webrtc/modules/audio_coding/neteq4/neteq_impl.h
+++ b/webrtc/modules/audio_coding/neteq4/neteq_impl.h
@@ -179,8 +179,12 @@
                            uint32_t receive_timestamp);
 
 
-  // Delivers 10 ms of audio to |output|. The number of samples produced is
-  // written to |output_length|. Returns 0 on success, or an error code.
+  // Delivers 10 ms of audio data. The data is written to |output|, which can
+  // hold (at least) |max_length| elements. The number of channels that were
+  // written to the output is provided in the output variable |num_channels|,
+  // and each channel contains |samples_per_channel| elements. If more than one
+  // channel is written, the samples are interleaved.
+  // Returns 0 on success, otherwise an error code.
   int GetAudioInternal(size_t max_length, int16_t* output,
                        int* samples_per_channel, int* num_channels);