Patch by Mike Lawther (mikelawther@chromium.org).

Patch by Mike Lawther (mikelawther@chromium.org).

The HTML5 canvas client of BlurDrawLooper needs the option to not apply the
canvas transform to the blur offset.

see
http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-elemen...
- "The shadowOffsetX and shadowOffsetY attributes specify the distance that the
shadow will be offset in the positive horizontal and positive vertical distance
respectively. Their values are in coordinate space units. They are not affected
by the current transformation matrix."

This patch is part of fixing
http://code.google.com/p/chromium/issues/detail?id=64647.

Review URL:  http://codereview.appspot.com/3391041/

git-svn-id: http://skia.googlecode.com/svn/trunk@631 2bbb7eff-a529-9590-31e7-b0007b416f81