WEBRTC_{BIG, LITTLE}_ENDIAN -> WEBRTC_ARCH_{BIG, LITTLE}_ENDIAN.

Mostly to remove a long-standing TODO...

TESTED=trybots
R=turaj@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2369005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5013 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.cc b/webrtc/modules/audio_processing/audio_processing_impl.cc
index edf20bc..b33049e 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl.cc
@@ -638,7 +638,7 @@
   if (size <= 0) {
     return kUnspecifiedError;
   }
-#if defined(WEBRTC_BIG_ENDIAN)
+#if defined(WEBRTC_ARCH_BIG_ENDIAN)
   // TODO(ajm): Use little-endian "on the wire". For the moment, we can be
   //            pretty safe in assuming little-endian.
 #endif