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);"

Change-Id: Idacd86ca09e22bf092422228599ae0d9bedded88
Reviewed-on: https://skia-review.googlesource.com/4543
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>