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

Source/modules/webgl/WebGLRenderbuffer.cpp

Index: Source/modules/webgl/WebGLRenderbuffer.cpp
diff --git a/Source/modules/webgl/WebGLRenderbuffer.cpp b/Source/modules/webgl/WebGLRenderbuffer.cpp
index 20183939e83b3af98756782189ae3dd78c874a1b..941e8b781662e8aced82720659f02920d2b6e3c5 100644
--- a/Source/modules/webgl/WebGLRenderbuffer.cpp
+++ b/Source/modules/webgl/WebGLRenderbuffer.cpp
@@ -31,17 +31,24 @@
 
 namespace blink {
 
-WebGLRenderbuffer* WebGLRenderbuffer::create(WebGLRenderingContextBase* ctx)
+PassRefPtrWillBeRawPtr<WebGLRenderbuffer> WebGLRenderbuffer::create(WebGLRenderingContextBase* ctx)
 {
-    return new WebGLRenderbuffer(ctx);
+    return adoptRefWillBeNoop(new WebGLRenderbuffer(ctx));
 }
 
 WebGLRenderbuffer::~WebGLRenderbuffer()
 {
+#if ENABLE(OILPAN)
     // This render buffer (heap) object must finalize itself.
     m_emulatedStencilBuffer.clear();
-
-    // See the comment in WebGLObject::detachAndDeleteObject().
+#endif
+    // Always call detach here to ensure that platform object deletion
+    // happens with Oilpan enabled. It keeps the code regular to do it
+    // with or without Oilpan enabled.
+    //
+    // See comment in WebGLBuffer's destructor for additional
+    // information on why this is done for WebGLSharedObject-derived
+    // objects.
     detachAndDeleteObject();
 }