Fix public issue #26: Take memory allocation and reallocation entirely out of the
Measure() loop. This gives all algorithms a small speed boost, except Snappy which
already didn't do reallocation (so the measurements were slightly biased in its
favor).

R=csilvers
DELTA=92  (69 added, 9 deleted, 14 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=1151


git-svn-id: https://snappy.googlecode.com/svn/trunk@24 03e5f5b5-db94-4691-08a0-1a8bf15f6143