SkTypes.h : move SkAutoMalloc into SkAutoMalloc.h

SkTypes.h : move SkAutoMalloc into SkAutoMalloc.h

  * SkAutoFree moved to SkTemplates.h (now implmented with unique_ptr).

  * SkAutoMalloc and SkAutoSMalloc moved to SkAutoMalloc.h

  * "SkAutoFree X(sk_malloc_throw(N));" --> "SkAutoMalloc X(N);"

Revert "Revert 'SkTypes.h : move SkAutoMalloc into SkAutoMalloc.h'"
This reverts commit c456b73fef9589bbdc5eb83eaa83e53c357bb3da.

Change-Id: Ie2c1a17c20134b8ceab85a68b3ae3e61c24fbaab
Reviewed-on: https://skia-review.googlesource.com/6886
Reviewed-by: Hal Canary <halcanary@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>