Revert "win: Make oilpan plugin work better with delayed template parsing."

tools/clang/blink_gc_plugin/tests/delayed_parsing.cpp

-#include "heap/stubs.h"
-
-namespace blink {
-
-struct HeapObject : public GarbageCollected<HeapObject> {
-    void trace(Visitor*) { }
-};
-
-template<typename T>
-class TemplateBase
-    : public GarbageCollected<TemplateBase<T> > {
-public:
-    void trace(Visitor* visitor) { visitor->trace(m_obj); }
-private:
-    Member<HeapObject> m_obj;
-};
-
-class Subclass : public TemplateBase<Subclass> {
-};
-
-}