Roll src/third_party/snappy/src/ 3f194acb5..156cd8939 (13 commits)

https://chromium.googlesource.com/external/github.com/google/snappy.git/+log/3f194acb57e0..156cd8939c5f

$ git log 3f194acb5..156cd8939 --date=short --no-merges --format='%ad %ae %s'
2019-06-13 cmumford Removed reference to deprecated autotools.
2019-05-25 costan Use GCC 9 on Travis CI
2019-05-16 cmumford The snappy landing page at http://google.github.io/snappy/ is served by [GitHub Pages](https://pages.github.com/) and lives in the gh-pages branch. This changes moves the page contents to a more easily accessed Markdown file.
2019-05-14 cmumford Minor typo fix in README.
2019-05-13 cmumford Sync TODO and comment processing with external repo.
2019-05-09 cmumford Changed CMake version from 3.4 to that in CMakeLists.txt in README.
2019-04-29 costan Update Travis CI configuration.
2019-04-22 cmumford Fixed formatted (bash/c++) sections of README.md.
2019-04-04 atdt Remove MSan exemption for _bzhi_u32, since LLVM now handles it correctly.
2019-04-25 5627721+abyss7 Fix compilation
2019-02-15 costan Remove MSBuild section from AppVeyor configuration.
2019-01-22 nafi Optimize snappy compression by about 2.2%.
2018-12-14 maikuolan Update README to use HTTPS instead of HTTP.

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

Change-Id: I3cc138dfb47116892c8baf9718d47e1b7f4798e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1694245Reviewed-by: Staphany Park <staphany@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675969}

DEPS

@@ -1310,7 +1310,7 @@ deps = {
     Var('chromium_git') + '/external/smhasher.git' + '@' + 'e87738e57558e0ec472b2fc3a643b838e5b6e88f',
 
   'src/third_party/snappy/src':
-    Var('chromium_git') + '/external/github.com/google/snappy.git' + '@' + '3f194acb57e0487531c96b97af61dcbd025a78a3',
+    Var('chromium_git') + '/external/github.com/google/snappy.git' + '@' + '156cd8939c5fba7fa68ae08db843377ecc07b4b5',
 
   'src/third_party/sqlite4java': {
       'packages': [