[wrapper-tracing] Fix write barrier in copy ctor

third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.h

Index: third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.h b/third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.h
index 39b25602ae48d5ab737c80c0c0996c2dc412209b..c5290f80a17ffb578506eb9040547e67c648953b 100644
--- a/third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.h
+++ b/third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.h
@@ -39,8 +39,7 @@ class TraceWrapperMember : public Member<T> {
    */
   TraceWrapperMember(const TraceWrapperMember& other) { *this = other; }

[Michael Lippautz, 2016/12/09 14:46:55]

The copy ctor did not forward to the explicitly defined operator=, but to some
compiler-generated one . This is because the signatures didn't match.

 
-  template <typename U>

[Michael Lippautz, 2016/12/09 14:46:55]

There's no sense in a different type U here.

-  TraceWrapperMember& operator=(const TraceWrapperMember<U>& other) {
+  TraceWrapperMember& operator=(const TraceWrapperMember& other) {
     DCHECK(other.m_parent);
     m_parent = other.m_parent;
     Member<T>::operator=(other);
@@ -48,16 +47,14 @@ class TraceWrapperMember : public Member<T> {
     return *this;
   }
 
-  template <typename U>
-  TraceWrapperMember& operator=(const Member<U>& other) {
+  TraceWrapperMember& operator=(const Member<T>& other) {
     DCHECK(!traceWrapperMemberIsNotInitialized());
     Member<T>::operator=(other);
     ScriptWrappableVisitor::writeBarrier(m_parent, other);
     return *this;
   }
 
-  template <typename U>
-  TraceWrapperMember& operator=(U* other) {
+  TraceWrapperMember& operator=(T* other) {
     DCHECK(!traceWrapperMemberIsNotInitialized());
     Member<T>::operator=(other);
     ScriptWrappableVisitor::writeBarrier(m_parent, other);