Move SkBenchLogger into separate files and make bench_pictures use it.
Remove sk_tools::print_msg, since SkBenchLogger is now used instead.
Combine picture_benchmark with bench_pictures, since that is the
only project that uses it.
Refactor the aggregator for bench timer data into its own class and
make bench_pictures use it.
Consolidate the various virtual PictureBenchmark::run functions
into one for reuse.
BUG=https://code.google.com/p/skia/issues/detail?id=822
Review URL: https://codereview.appspot.com/6488086
git-svn-id: http://skia.googlecode.com/svn/trunk@5432 2bbb7eff-a529-9590-31e7-b0007b416f81
