This pattern (read-only base, writable subclass) was picked to maintain a *Buffer option that doesn't copy the source bits when parsing. ByteBuffer and Buffer both copy. I'm open to discussion on what the type relationship would be, though :)
Tests have been added to ensure the symmetric nature of read/write operations.
BUG=
R=bcornell@google.com, pthatcher@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/45259005
Cr-Commit-Position: refs/heads/master@{#9107}
Provides a read-only interface for reading byte and bit-sized data from
an underlying buffer in network/big-endian order. Also provides a method
for reading exponential golomb encoded values, which will be useful in
H.264 packet parsing (separate CL).
BUG=
R=pthatcher@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/49719004
Cr-Commit-Position: refs/heads/master@{#9046}
