Prototype code that turns any/every flattenable into JSON

This makes inspecting things in SkDebugger far more useful - any filter
or other complex object on the paint is ultimately visible. You still
have to do some guess work to figure out what the fields actually mean,
but you can at least cross-reference with the code in flatten().

Screenshots:
Before: https://screenshot.googleplex.com/a6JM5HBBe6G.png
After : https://screenshot.googleplex.com/XQfr4YJ6mnH.png

Changes to public API are just removals and changes to make
some functions virtual.

TBR=reed@google.com

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1920423002

Review-Url: https://codereview.chromium.org/1920423002

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/ColorFilterTest.cpp b/tests/ColorFilterTest.cpp
index cf542db9fa..9dfadbbb84 100644
--- a/tests/ColorFilterTest.cpp
+++ b/tests/ColorFilterTest.cpp
@@ -16,7 +16,7 @@
 #include "Test.h"
 
 static sk_sp<SkColorFilter> reincarnate_colorfilter(SkFlattenable* obj) {
-    SkWriteBuffer wb;
+    SkBinaryWriteBuffer wb;
     wb.writeFlattenable(obj);
 
     size_t size = wb.bytesWritten();