Move GrResourceProvider::createMipMappedTexture to GrSurfaceProxy::MakeDeferredMipMap

Although this adds a new method to GrResourceProvider, it is a slight improvement in that it removes some GrProxy stuff from GrResourceProvider (which arguably should only deal in GrSurface-derived classes).

Bug: skia:
Change-Id: I6d097ed178cd2aa5662770a164135bf2553b80e6
Reviewed-on: https://skia-review.googlesource.com/22023
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
8 files changed