Move SkGpuDevice::internalDrawPath to GrBlurUtils::drawPathWithMaskFilter

This CL is ugly but it:

removes the stored SkGpuDevice back pointer from GrTextContext (at the cost of passing more parameters)
moves SkGpuDevice::internalDrawPath to GrDrawContext::drawPathFull

Unfortunately, the GrTextContext-derived classes still need the SkGpuDevice for filterTextFlags calls but I will try removing that in a separate CL.

Review URL: https://codereview.chromium.org/1157773003
13 files changed