Rename SmartPointer to SmartArrayPointer.

Rename SmartPointer to SmartArrayPointer.

As pointed out in: http://codereview.chromium.org/7754007/#msg5

"SmartPointer should have been named SmartArrayPointer as it expects an input
allocated using new[] and deallocates it using delete[]. Using it as a simple
scoped pointer for a single object is incorrect."

R=vitalyr@chromium.org

Signed-off-by: Thiago Farina <tfarina@chromium.org>;