Autorename:
  autorename_* files are renamed copies of various files that would cause
    base name collisions from mac libtool. These files are generated
    by generate_gn.py. https://chromium-review.googlesource.com/#/c/274543/

Current patches:
  .gitignore
    Has a "Chromium stuff" section.

  compat/msvcrt/{snprintf.c,snprintf.h}
  compat/{strtod.c,strtod.h}
    Commit b5269bfb48c71fe17c02eee00c71b1e9762497db changes these files and
    relevant build rules to fix inconsistent linkage when building with MSVC.
    The rules/files expose overriden symbols as externs and force inject these
    headers when building with the component build.
    strtod.h was added, so it may not appear in diffs that ignore additions.
    f3299330654ac1b40c50b3cbcae619f42eb7d838 added an include to snprintf.c.
    4fe9bb85b83fffe4c3640493ef6655b0992a822c re-adds an "undef strod" and
    new strtod decl to fix Windows compilation issues to strtod.c .

  configure
    Commented out a section that creates symlink for source_path. Using symlink
    causes windows builds to fail (cl.exe cant find the files).

    Commented out pkg-config checks for libopus since we use Chromium's
    copy.

  !!!SECURITY SENSITIVE ISSUE PLEASE VERIFY AFTER EACH FFMPEG ROLL!!!
  Remove UNCHECKED_BITSTREAM_READER defines in libavcodec/
    Remove "#define UNCHECKED_BITSTREAM_READER 1" from all codecs.
    In Chromium, all codecs should use the safe bitstream reader.

  libavformat/log.{c,h}
  libavformat/internal.{h}
    Changes to #define logging functions to nothing to save ~158kb of strings.

  libavformat/mov.c
    Always use av_realloc() for |extradata|. https://crbug.com/721872

  libavformat/matroskadec.c
    Add CONFIG_LZO and CONFIG_SIPR_DECODER (and other CONFIG_*) checks to remove
    code that may be a security risk. Discuss with cevans@ before removing.

    Remove extra const from static EbmlSyntax arrays. This fixes windows
    compile error C4114, since EbmlSyntax struct is already defined with const.
    TODO: push upstream.

  libavformat/mp3dec.c
    Don't change the start_time in mp3_parse_info_tag as Chromium should handle
    it. https://crbug.com/504623

    Change to mp3_read_header: check for the custom "skip_id3v1_tag" metadata
    flag we set in Chromium code, to avoid the costly reads of id3v1 tags.
    Also av_dict_free the dictionary before overwriting it to prevent leaks.
    See crbug.com/703965 (upstream patch discussion:
    http://ffmpeg.org/pipermail/ffmpeg-devel/2017-April/209953.html).

  libavformat/wavdec.c
    Exclude code blocks using #if to remove references to symbols not in our
    builds which some toolchains don't elide, for each of
    CONFIG_SPDIF_DEMUXER and CONFIG_W64_DEMUXER.

  libavutil/mem.c
    Enable av_max_alloc(0) to remove alloc size bound.

  libavutil/x86/x86inc.asm
    https://chromium-review.googlesource.com/#/c/272274/
    Fixes the conditionals on Linux so that these symbols are hidden and
    adds the Chromium-specific private_extern extension for hiding these
    symbols on OSX.

  libavcodec/mips/aacdec_mips.c
    update_ltp_mips() function fails to compile:
        "error: couldn't allocate output register for constraint 'r'"

  libavformat/utils.c
    av_read_frame() : Prevent undefined shift with wrap_bits > 63. Pushed to
    upstream, so should be upstream by M66 roll. http://crbug.com/783459

  libavformat/oggdec.c
    Removes CELT, DIRAC, DAALA, and SPEEX support form the ogg parser. We don't
    support these codecs and the parsers have bugs. http://crbug.com/654612

  libavformat/mov.c
    find_prev_closest_index(): It's possible *ctts_index == ctts_count. Thus add
    a check to prevent access violation. https://crbug.com/804097

  libavcodec/h264_cavlc.c
    When ff_h264_decode_mb_cavlc() failed due to wrong sl->qscale values, e.g.
    dquant out of range, set the qscale to be a valid value before returning -1
    and exiting the function. The qscale value can be used later, e.g. in loop
    filter and keeping an invalid qscale could cause trouble.
    https://crbug.com/806122

  libavformat/mov.c
    mov_read_stts(): Fix stts memory allocation (use i + 1 instead of i).
    https://crbug.com/801821

  libavformat/mov.c
    mov_read_trun(): Fix memset size on ctts_data. https://crbug.com/812567
