This feeds into efforts to create a working install target.
The order of headers is still funky, and was "fixed" by clang-format,
but in a way that doesn't exactly align with the style guide. Further
cleanup of header order is coming in a follow-up PR.
LOG(FATAL) aborts the executable, which means gtest can't write any
reports it might be configured to write when tests are complete. This
will interfere with reporting.
This converts the only use of LOG(FATAL), which was in
ReadTestDataFile(), to LOG(ERROR). This also updates test cases to avoid
crashing when ReadTestDataFile() returns an empty buffer.
Implemented according to bitstream spec at
https://aomediacodec.github.io/av1-spec/.
It will be used to do AV1 subsample encryption later.
Issue #453.
Change-Id: I84d8a2a780d95f2c9f430ee598838b97474cc0af