Support Canvas Clip on Blit Framebuffer

The previous fix to blit framebuffer didn't take cases where
the canvas had a clip applied into account. Fix and update
the unit test to add this case.

Bug: 658277
Change-Id: If3a9d2c8ddf955164cf529c9d6036618f957e426
Reviewed-on: https://skia-review.googlesource.com/11300
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
2 files changed