Reorganize BRD code in new tools directory

Rename SkCodecTools.h to SkBitmapRegionDecoderPriv.h

Move BRD code to its own directory in tools.  This
allows us to not need to expose the entire tools
directory in Android.

BUG=skia:

Review URL: https://codereview.chromium.org/1417393004
13 files changed