added JSON support for various lesser-used features
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1690613002

Review URL: https://codereview.chromium.org/1690613002
diff --git a/tools/debugger/SkDrawCommand.h b/tools/debugger/SkDrawCommand.h
index a93461a..c0ab3a0 100644
--- a/tools/debugger/SkDrawCommand.h
+++ b/tools/debugger/SkDrawCommand.h
@@ -528,11 +528,15 @@
                        const SkPoint texCoords[4], SkXfermode* xmode,
                        const SkPaint& paint);
     void execute(SkCanvas* canvas) const override;
+    Json::Value toJSON() const override;
+    static SkDrawPatchCommand* fromJSON(Json::Value& command);
 
 private:
     SkPoint fCubics[12];
-    SkColor fColors[4];
-    SkPoint fTexCoords[4];
+    SkColor* fColorsPtr;
+    SkColor  fColors[4];
+    SkPoint* fTexCoordsPtr;
+    SkPoint  fTexCoords[4];
     SkAutoTUnref<SkXfermode> fXfermode;
     SkPaint fPaint;