Add GrTextureOp and use to implement SkGpuDevice::drawImage[Rect]() when possible

This op draws a texture rectangle in src over blending with no edge antialiasing. It less powerful than NonAAFillRectOp/GrPaint but has less CPU overhead.

Change-Id: Ia6107bb67c1c2a83de14c665aff64b0de2750fba
Reviewed-on: https://skia-review.googlesource.com/33802
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
12 files changed