Fix modules_unittests on iOS.

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc

Index: webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
diff --git a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
index c6c0406128f05d2c818b0a94212ea5cb1377bc60..acb2a07dd93af0ec35e082e07521f369d4f2b62f 100644
--- a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
+++ b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.cc
@@ -267,7 +267,7 @@ bool H264AnnexBBufferHasVideoFormatDescription(const uint8_t* annexb_buffer,
   // Start code + access unit delimiter + start code = 4 + 2 + 4 = 10.
   if (!is_first_nalu_type_aud || annexb_buffer_size <= 10u)
     return false;
-  NaluType second_nalu_type = ParseNaluType(annexb_buffer[10]);
+  NaluType second_nalu_type = ParseNaluType(annexb_buffer[9]);

[sprang_webrtc, 2016/09/21 08:05:33]

nit: Use named constants for offsets.

[tkchin_webrtc, 2016/09/27 11:01:47]

I don't follow this one
0-3: start code
4-5: access unit delimiter
6-9: start code

Shouldn't 10 be correct?

[kthelgason, 2016/09/27 11:10:31]

At least the way the test is set up it's:
0-3: start code
4:     nalu type
5-8: start code

Perhaps it's the test that's wrong, not the implementation.

[tkchin_webrtc, 2016/09/27 13:51:56]

Can you double check the h264 spec to see how long auds are? Not sure which is
incorrect here.

   bool is_second_nalu_type_sps = second_nalu_type == kSps;
   return is_second_nalu_type_sps;
 }