Rename wrap backend tex/rt methods on GrProxyProvider

This makes them more consistent with similar methods on GrResourceProvider.

Change-Id: Ice7e5dbe8100481781015b386445e9b7101bd75e
Reviewed-on: https://skia-review.googlesource.com/112821
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
10 files changed