WebPPictureAllocARGB: align argb allocation
WebPPictureAllocARGB: align argb allocation

Change-Id: Ib390e8bbb97b38316a38af6a33e8a26bd050ee16

PKRoma/libwebp,PKRoma/libwebp,webmproject/libwebp,PKRoma/libwebp,PKRoma/libwebp,PKRoma/libwebp,webmproject/libwebp,webmproject/libwebp,PKRoma/libwebp,webmproject/libwebp,webmproject/libwebp