GitLab

This patch reworks the SSL session caching scheme for OpenSSL
client sockets, as an attempt to get rid of the mysterious crashes
described at http://crbug.com/298606

- Move the internal SSLSessionCache class to its own source file,
  while renaming it as SSLSessionCacheOpenSSL.

- Change the session caching logic to:

  - Completely disable OpenSSL's builtin cache.
  - Implement Session ID generation (and uniqueness check).
  - Implement eviction and expiration detection.

- Add a unit test for SSLSessionCacheOpenSSL.

- Modify SSLClientSocketOpenSSL implementation to use the new cache.

BUG=298606
R=rsleevi@chromium.org,agl@chromium.org,wtc@chromium.org

Review URL: https://codereview.chromium.org/89623002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238398 0039d316-1c4b-4281-b951-d872f2087c98