Fix bug of SkSVGCanvas::Make

The method `SkSVGCanvas::Make(const SkRect& bounds, SkWStream* writer)`
passes a pointer to a stack-allocated object to the returned SkCanvas.

TBR=
Change-Id: Ica7933adc59764a69eb2fb6312df91ffffd5627b
Reviewed-on: https://skia-review.googlesource.com/c/192040
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
5 files changed