Roll src/third_party/snappy/src/ b02bfa754..ca37ab7fb (5 commits)

https://chromium.googlesource.com/external/github.com/google/snappy.git/+log/b02bfa754ebf..ca37ab7fb9b7

$ git log b02bfa754..ca37ab7fb --date=short --no-merges --format='%ad %ae %s'
2018-02-02 jgorbe Ensure DecompressAllTags starts on a 32-byte boundary + 16 bytes.
2018-01-16 scrubbed Fix an incorrect analysis / comment in the "pattern doubling" code.
2018-01-04 costan Fix Travis CI configuration for OSX.
2017-12-21 chandlerc Rework a very hot, very sensitive part of snappy to reduce the number of instructions, the number of dynamic branches, and avoid a particular loop structure than LLVM has a very hard time optimizing for this particular case.
2017-12-20 costan Fix generated version number in open source release.

Created with:
  roll-dep src/third_party/snappy/src

Change-Id: I45f0f9e6aa7c81daef1172d39cef0a16814ccf20
Reviewed-on: https://chromium-review.googlesource.com/924573


Reviewed-by: Chris Mumford <cmumford@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537925}