SkBitmap::scrollRect changes pixels, but only if not immutable.

scrollRect will now return false if the bitmap is immutable, and
call notifyPixelsChanged when changing the pixels. This will give
the bitmap a new generation ID.

Review URL: https://codereview.appspot.com/6480046

git-svn-id: http://skia.googlecode.com/svn/trunk@5230 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed