Make SkAutoTMalloc movable

BUG=skia:

Change-Id: I683407659c252656445b92734484170587c2f75a
Reviewed-on: https://skia-review.googlesource.com/8360
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed