Templetized SkWriter32 readTAt() & overwriteTAt()

Convert SkWriter32::{read,write}32At() to ::{read,overwrite}TAt<>() to allow
peeking/updating arbitrary records.


BUG=skia:
R=mtklein@google.com, reed@google.com, robertphillips@google.com, iancottrell@chromium.org

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/130913018

git-svn-id: http://skia.googlecode.com/svn/trunk@13416 2bbb7eff-a529-9590-31e7-b0007b416f81
6 files changed