Merge the 2018-05-05 SPL branch from AOSP-Partner into android-7.1.2_r36

* origin/security-aosp-nyc-mr2-release:
  Fix SkFILEStream.
  Fix truncated webp images DO NOT MERGE
  Defend against ICOs with large BMPs embedded DO NOT MERGE
  Stop supporting kUnknown_BmpHeaderType DO NOT MERGE
  Set a limit on the size for BMP images DO NOT MERGE

Issue: FP2N-106
Change-Id: Ibb1916231193b85c68037885c2422aa363d75f4c