Move SkDrawLooper implementation to its own file.

It previously lived in SkPaint.cpp.

BUG=
R=reed@google.com, tomhudson@chromium.org, jbroman@chromium.org

Author: jbroman@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15896004

git-svn-id: http://skia.googlecode.com/svn/trunk@9272 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed