blink_gc_plugin: retire overloaded traceImpl detection and handling.

tools/clang/blink_gc_plugin/tests/traceimpl_overloaded.cpp

Index: tools/clang/blink_gc_plugin/tests/traceimpl_overloaded.cpp
diff --git a/tools/clang/blink_gc_plugin/tests/traceimpl_overloaded.cpp b/tools/clang/blink_gc_plugin/tests/traceimpl_overloaded.cpp
index e5a2fee6c13a754e3a2ceae4c8a4f21391e19716..ed04f8276c0d41c35aaad73ddee4f8b97faaa881 100644
--- a/tools/clang/blink_gc_plugin/tests/traceimpl_overloaded.cpp
+++ b/tools/clang/blink_gc_plugin/tests/traceimpl_overloaded.cpp
@@ -7,28 +7,10 @@
 namespace blink {
 
 void ExternBase::Trace(Visitor* visitor) {
-  TraceImpl(visitor);
-}
-
-void ExternBase::Trace(InlinedGlobalMarkingVisitor visitor) {
-  TraceImpl(visitor);
-}
-
-template <typename VisitorDispatcher>
-inline void ExternBase::TraceImpl(VisitorDispatcher visitor) {
   visitor->Trace(x_base_);
 }
 
 void ExternDerived::Trace(Visitor* visitor) {
-  TraceImpl(visitor);
-}
-
-void ExternDerived::Trace(InlinedGlobalMarkingVisitor visitor) {
-  TraceImpl(visitor);
-}
-
-template <typename VisitorDispatcher>
-inline void ExternDerived::TraceImpl(VisitorDispatcher visitor) {
   visitor->Trace(x_derived_);
   ExternBase::Trace(visitor);
 }