Revision 1293057

[jira] [HBASE-5470] Make DataBlockEncodingTool work correctly with no native
compression codecs loaded

Summary:
DataBlockEncodingTool was fixed as part of porting data block encoding
(HBASE-4218) to 89-fb
(https://reviews.facebook.net/rHBASEEIGHTNINEFBBRANCH1245291,
https://reviews.facebook.net/D1659). The bug being fixed here appeared when
using GZ as baseline compression codec but not loading native Hadoop libraries,
in which case the compressor instance would be null.

Test Plan:
Run DataBlockEncoding tool with GZ (no native codecs) and LZO (with native
codecs) as baseline (Hadoop-level) compression codecs

Reviewers: JIRA, Kannan, mcorgan, lhofhansl, todd, stack, tedyu

Reviewed By: tedyu

Differential Revision: https://reviews.facebook.net/D1917