Reset indexer upon initialization in AudioLoop.

webrtc/modules/audio_coding/neteq/tools/audio_loop.cc

Index: webrtc/modules/audio_coding/neteq/tools/audio_loop.cc
diff --git a/webrtc/modules/audio_coding/neteq/tools/audio_loop.cc b/webrtc/modules/audio_coding/neteq/tools/audio_loop.cc
index eed95753f0f3e2ea636c429562fb650e57ce2d66..56765aaefa45bdc205e7f6b565affae1a76b074b 100644
--- a/webrtc/modules/audio_coding/neteq/tools/audio_loop.cc
+++ b/webrtc/modules/audio_coding/neteq/tools/audio_loop.cc
@@ -40,6 +40,7 @@ bool AudioLoop::Init(const std::string file_name,
 
   loop_length_samples_ = samples_read;
   block_length_samples_ = block_length_samples;
+  next_index_ = 0;
   return true;
 }