Moved Canvas->JSON and JSON->Canvas functionality into SkDebugCanvas.
SkJSONCanvas and SkJSONRenderer will be deleted once the debug server
has been updated.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1681643002

Committed: https://skia.googlesource.com/skia/+/32fff1ba0c759d97ab78320b7ae46dd7696a4e6e

Committed: https://skia.googlesource.com/skia/+/46cb6d6b82b0ab71033aef91419e8beae25bb8a4

Review URL: https://codereview.chromium.org/1681643002
5 files changed