Move npot resizing out of GrContext and simplify GrContext texture functions.

Committed: https://skia.googlesource.com/skia/+/8a8100349105c8c6de39fcb34e47679da7a67f54

Committed: https://skia.googlesource.com/skia/+/6c96672491b04cb782bce8fee778124df66524a0

Review URL: https://codereview.chromium.org/882223003
10 files changed