Always prefix OBUs with a size field.

- Make the add_4bytes_obusize experiment part of the obu experiment.
- Remove the add_4bytes_obusize experiment flags.
- Update the encoder, decoder, and tooling sources.

BUG=aomedia:1125

Change-Id: Ia5c443c855e52618257b39c44ca2632703bf83fd

av1/decoder/decodeframe.c

diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index 23073e8..15adb74 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -1797,12 +1797,7 @@
       aom_internal_error(error_info, AOM_CODEC_CORRUPT_FRAME,
                          "Truncated packet or corrupt tile size");
   } else {
-#if !CONFIG_OBU || CONFIG_ADD_4BYTES_OBUSIZE
     size = data_end - *data;
-#else
-    size = mem_get_varsize(*data, tile_size_bytes);
-    *data += tile_size_bytes;
-#endif
   }
 
   buf->data = *data;
@@ -1838,6 +1833,7 @@
   for (int r = 0; r < tile_rows; ++r) {
     for (int c = 0; c < tile_cols; ++c, ++tc) {
       TileBufferDec *const buf = &tile_buffers[r][c];
+
 #if CONFIG_OBU
       const int is_last = (tc == endTile);
       const size_t hdr_offset = 0;

av1/decoder/obu.c

diff --git a/av1/decoder/obu.c b/av1/decoder/obu.c
index 6416ece..67e9bb9 100644
--- a/av1/decoder/obu.c
+++ b/av1/decoder/obu.c
@@ -169,14 +169,10 @@
 
     av1_init_read_bit_buffer(pbi, &rb, data + PRE_OBU_SIZE_BYTES, data_end);
 
-// every obu is preceded by PRE_OBU_SIZE_BYTES-byte size of obu (obu header +
-// payload size)
-// The obu size is only needed for tile group OBUs
-#if CONFIG_ADD_4BYTES_OBUSIZE
+    // every obu is preceded by PRE_OBU_SIZE_BYTES-byte size of obu (obu header
+    // + payload size)
+    // The obu size is only needed for tile group OBUs
     const size_t obu_size = mem_get_le32(data);
-#else
-    const size_t obu_size = (size_t)(data_end - data);
-#endif
     const OBU_TYPE obu_type = read_obu_header(&rb, &obu_header_size);
     data += (PRE_OBU_SIZE_BYTES + obu_header_size);
 

av1/decoder/obu.h

diff --git a/av1/decoder/obu.h b/av1/decoder/obu.h
index fec25fb..fe7d2ad 100644
--- a/av1/decoder/obu.h
+++ b/av1/decoder/obu.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ * Copyright (c) 2017, Alliance for Open Media. All rights reserved
  *
  * This source code is subject to the terms of the BSD 2 Clause License and
  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License