Revert of Move speech module over to Oilpan.

Source/heap/Visitor.h

Index: Source/heap/Visitor.h
diff --git a/Source/heap/Visitor.h b/Source/heap/Visitor.h
index 0dc62ab25c9f1f65954d087c797272b87e0e0eff..864dd884aa687f9bd42887928369db9701f09563 100644
--- a/Source/heap/Visitor.h
+++ b/Source/heap/Visitor.h
@@ -319,18 +319,6 @@
 #endif
     }
 
-    // Similarly, this trace method is to trace a RawPtrWillBeMember
-    // when ENABLE(OILPAN) is not enabled.
-    // Remove this once we remove RawPtrWillBeMember.
-    template<typename T>
-    void trace(const RawPtr<T>&)
-    {
-#if ENABLE(OILPAN)
-        // RawPtrs should never be traced.
-        ASSERT_NOT_REACHED();
-#endif
-    }
-
     // This method marks an object and adds it to the set of objects
     // that should have their trace method called. Since not all
     // objects have vtables we have to have the callback as an