Reland SkWriter32 growth change with build fixes.

  - SkSWriter32 resets itself with its stack block;
  - Track the full capacity of fInternal (which may be >size after a reset).

BUG=skia:2125
R=reed@google.com, iancottrell@chromium.org, iancottrell@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/158953003

git-svn-id: http://skia.googlecode.com/svn/trunk@13412 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed