Introduce a macro enabling 'SimpleClassVectorTraits'

Source/platform/heap/HeapTest.cpp

Index: Source/platform/heap/HeapTest.cpp
diff --git a/Source/platform/heap/HeapTest.cpp b/Source/platform/heap/HeapTest.cpp
index 39a05e3e8468307fdafcd0b98f9e12e7233bcb61..248272cc43c2a8f04cfc000b8f71c7008798862f 100644
--- a/Source/platform/heap/HeapTest.cpp
+++ b/Source/platform/heap/HeapTest.cpp
@@ -1264,14 +1264,9 @@ private:
 
 } // WebCore namespace
 
-namespace WTF {
-
-// We need the below vector trait specialization for the above HeapVectors to behave correctly wrt. memset, memcmp etc.
-template<> struct VectorTraits<WebCore::VectorObject> : public SimpleClassVectorTraits<WebCore::VectorObject> { };
-template<> struct VectorTraits<WebCore::VectorObjectInheritedTrace> : public SimpleClassVectorTraits<WebCore::VectorObjectInheritedTrace> { };
-template<> struct VectorTraits<WebCore::VectorObjectNoTrace> : public SimpleClassVectorTraits<WebCore::VectorObjectNoTrace> { };
-
-} // WTF namespace
+WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(WebCore::VectorObject);
+WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(WebCore::VectorObjectInheritedTrace);
+WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(WebCore::VectorObjectNoTrace);
 
 namespace WebCore {