Move SwizzleCoreAudioLayout5_1() closer to where it's called.

media/audio/mac/audio_low_latency_output_mac.cc

Index: media/audio/mac/audio_low_latency_output_mac.cc
diff --git a/media/audio/mac/audio_low_latency_output_mac.cc b/media/audio/mac/audio_low_latency_output_mac.cc
index e63477630c119a260b1449f4c7f26856c7b80897..eb8eb1c74d769eb98713fac561029995b2ac777b 100644
--- a/media/audio/mac/audio_low_latency_output_mac.cc
+++ b/media/audio/mac/audio_low_latency_output_mac.cc
@@ -11,7 +11,22 @@
 #include "media/audio/audio_util.h"
 #include "media/audio/mac/audio_manager_mac.h"
 
-using media::SwizzleCoreAudioLayout5_1;
+// Reorder PCM from AAC layout to Core Audio 5.1 layout.
+// TODO(fbarchard): Switch layout when ffmpeg is updated.
+template<class Format>
+static void SwizzleCoreAudioLayout5_1(Format* b, uint32 filled) {
+  static const int kNumSurroundChannels = 6;
+  Format aac[kNumSurroundChannels];
+  for (uint32 i = 0; i < filled; i += sizeof(aac), b += kNumSurroundChannels) {
+    memcpy(aac, b, sizeof(aac));
+    b[0] = aac[1];  // L
+    b[1] = aac[2];  // R
+    b[2] = aac[0];  // C
+    b[3] = aac[5];  // LFE
+    b[4] = aac[3];  // Ls
+    b[5] = aac[4];  // Rs
+  }
+}
 
 // Overview of operation:
 // 1) An object of AUAudioOutputStream is created by the AudioManager