Fix bug where SkGPipe'ed clips do not happen.

Modify SkGPipeCanvas::clipRect and ::clipPath so they correctly
override the SkCanvas versions, and therefore get called. Also use
SK_OVERRIDE for its virtual functions to help catch this in the
future.

BUG=572
Review URL: https://codereview.appspot.com/6055050

git-svn-id: http://skia.googlecode.com/svn/trunk@3718 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed