Revert of [Oilpan] Migrate classes under module/webgl onto oilpan heap

Source/modules/webgl/OESStandardDerivatives.h

Index: Source/modules/webgl/OESStandardDerivatives.h
diff --git a/Source/modules/webgl/OESStandardDerivatives.h b/Source/modules/webgl/OESStandardDerivatives.h
index 43ba2e3b3db4c83c819c00d5098f2d039646d11c..6c1e7c73a970bc1e0544bc94f840d97a3ca01081 100644
--- a/Source/modules/webgl/OESStandardDerivatives.h
+++ b/Source/modules/webgl/OESStandardDerivatives.h
@@ -27,13 +27,14 @@
 #define OESStandardDerivatives_h
 
 #include "modules/webgl/WebGLExtension.h"
+#include "wtf/PassRefPtr.h"
 
 namespace blink {
 
 class OESStandardDerivatives final : public WebGLExtension {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static OESStandardDerivatives* create(WebGLRenderingContextBase*);
+    static PassRefPtrWillBeRawPtr<OESStandardDerivatives> create(WebGLRenderingContextBase*);
     static bool supported(WebGLRenderingContextBase*);
     static const char* extensionName();