blink_gc_plugin: retire overloaded traceImpl detection and handling.

tools/clang/blink_gc_plugin/tests/legacy_naming/traceimpl_error.h

Index: tools/clang/blink_gc_plugin/tests/legacy_naming/traceimpl_error.h
diff --git a/tools/clang/blink_gc_plugin/tests/legacy_naming/traceimpl_error.h b/tools/clang/blink_gc_plugin/tests/legacy_naming/traceimpl_error.h
index 5a883b4e56261467156cab1c1520e224eb9d5398..0960199e1f94d90e25def6df92c43bc809ac5899 100644
--- a/tools/clang/blink_gc_plugin/tests/legacy_naming/traceimpl_error.h
+++ b/tools/clang/blink_gc_plugin/tests/legacy_naming/traceimpl_error.h
@@ -17,10 +17,7 @@ class X : public GarbageCollected<X> {
 class TraceImplInlinedWithUntracedMember
     : public GarbageCollected<TraceImplInlinedWithUntracedMember> {
  public:
-  void trace(Visitor* visitor) { traceImpl(visitor); }
-
-  template <typename VisitorDispatcher>
-  void traceImpl(VisitorDispatcher visitor) {
+  void trace(Visitor* visitor) {
     // Empty; should get complaints from the plugin for untraced x_.
   }
 
@@ -33,9 +30,6 @@ class TraceImplExternWithUntracedMember
  public:
   void trace(Visitor* visitor);
 
-  template <typename VisitorDispatcher>
-  inline void traceImpl(VisitorDispatcher);
-
  private:
   Member<X> x_;
 };
@@ -47,10 +41,7 @@ class Base : public GarbageCollected<Base> {
 
 class TraceImplInlineWithUntracedBase : public Base {
  public:
-  void trace(Visitor* visitor) override { traceImpl(visitor); }
-
-  template <typename VisitorDispatcher>
-  void traceImpl(VisitorDispatcher visitor) {
+  void trace(Visitor* visitor) override {
     // Empty; should get complaints from the plugin for untraced Base.
   }
 };
@@ -58,9 +49,6 @@ class TraceImplInlineWithUntracedBase : public Base {
 class TraceImplExternWithUntracedBase : public Base {
  public:
   void trace(Visitor*) override;
-
-  template <typename VisitorDispatcher>
-  void traceImpl(VisitorDispatcher visitor);
 };
 
 }