Convert the SkiaBenchmarkingExtension to a gin::Wrappable class

content/renderer/gpu/gpu_benchmarking_extension.cc

Index: content/renderer/gpu/gpu_benchmarking_extension.cc
diff --git a/content/renderer/gpu/gpu_benchmarking_extension.cc b/content/renderer/gpu/gpu_benchmarking_extension.cc
index b5399fb1f38e60bad79f1dab29177ae6f16e9c5b..4736d142450a87a10281b3de3fe7ffaf324093e1 100644
--- a/content/renderer/gpu/gpu_benchmarking_extension.cc
+++ b/content/renderer/gpu/gpu_benchmarking_extension.cc
@@ -71,7 +71,7 @@ class SkPictureSerializer {
         layer_id_(0) {
     // Let skia register known effect subclasses. This basically enables
     // reflection on those subclasses required for picture serialization.
-    content::SkiaBenchmarkingExtension::InitSkGraphics();
+    content::SkiaBenchmarking::Initialize();
   }
 
   // Recursively serializes the layer tree.