Revert of default SkPixelSerializer

tools/sk_tool_utils.h

Index: tools/sk_tool_utils.h
diff --git a/tools/sk_tool_utils.h b/tools/sk_tool_utils.h
index dab42e31fdc8cecb335887198039124e923e06ae..67fd869a878d196d0cef66a84cb77462b2c6dcda 100644
--- a/tools/sk_tool_utils.h
+++ b/tools/sk_tool_utils.h
@@ -113,6 +113,18 @@
 
     SkBitmap create_string_bitmap(int w, int h, SkColor c, int x, int y,
                                   int textSize, const char* str);
+
+    // Encodes to PNG, unless there is already encoded data, in which case that gets
+    // used.
+    class PngPixelSerializer : public SkPixelSerializer {
+    public:
+        bool onUseEncodedData(const void*, size_t) override { return true; }
+        SkData* onEncodePixels(const SkImageInfo& info, const void* pixels,
+                               size_t rowBytes) override {
+            return SkImageEncoder::EncodeData(info, pixels, rowBytes,
+                                              SkImageEncoder::kPNG_Type, 100);
+        }
+    };
 
     // A helper for inserting a drawtext call into a SkTextBlobBuilder
     void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const SkPaint& origPaint,