Rename benchmark classes, hopefully less confusing to valgrid?

I was able to reproduce the problem, but Valgrind was giving me a very odd
report, pointing to a particular line in QuadTreeBench.cpp from a stack that
was running RTreeBench.

Whenever Valgrind complains, it's always about switch(fQuery), line 109 in
QuadTreeBench or 119 in RTreeBench.  I can't see any way that fQuery is not
initialized.

I believe we've just confused Valgrind by linking together  classes with
identical names.  This CL gives them all unique names.

BUG=skia:2455
R=bungeman@google.com, mtklein@google.com, bsalomon@google.com, borenet@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/247913003

git-svn-id: http://skia.googlecode.com/svn/trunk@14338 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed