Eliminate uses of Skia's SkDELETE macro

Skia no longer uses these macros internally.  They're now only
provided for backwards compatibility, so remove their uses within
Android.

See thread on skia-discuss:
https://groups.google.com/d/msg/skia-discuss/l9TSgpYCHpU/sNpA1y8YCQAJ

Change-Id: Ia7313f5bbdf4d2d9fb4a10fc5bdc1572e6b84f6c