BlinkGCPlugin: require GC mixin instances to declare local trace().

tools/clang/blink_gc_plugin/tests/heap/stubs.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEAP_STUBS_H_
 #define HEAP_STUBS_H_
 
 #include "stddef.h"
 
 #define WTF_MAKE_FAST_ALLOCATED                 \
@@ skipping 124 matching lines @@
 
 #define ALLOW_ONLY_INLINE_ALLOCATION()    \
     public:                               \
     void* operator new(size_t, void*);    \
     private:                              \
     void* operator new(size_t) = delete;
 
 #define GC_PLUGIN_IGNORE(bug)                           \
     __attribute__((annotate("blink_gc_plugin_ignore")))
 
-#define USING_GARBAGE_COLLECTED_MIXIN(type)             \
-    public:                                             \
-    virtual void adjustAndMark(Visitor*) const {}       \
-    virtual bool isAlive(Visitor*) const { return 0; }
+#define USING_GARBAGE_COLLECTED_MIXIN(type)                     \
+public:                                                         \
+    virtual void adjustAndMark(Visitor*) const override { }     \
+    virtual bool isHeapObjectAlive(Visitor*) const override { return 0; }
 
 template<typename T> class GarbageCollected { };
 
 template<typename T>
 class GarbageCollectedFinalized : public GarbageCollected<T> { };
 
 template<typename T> class Member {
 public:
     operator T*() const { return 0; }
     T* operator->() { return 0; }
@@ skipping 52 matching lines @@
     void trace(const T&);
 };
 
 class Visitor : public VisitorHelper<Visitor> {
  public:
     template<typename T, void (T::*method)(Visitor*)>
     void registerWeakMembers(const T* obj);
 };
 
 class GarbageCollectedMixin {
+public:
     virtual void adjustAndMark(Visitor*) const = 0;
-    virtual bool isAlive(Visitor*) const = 0;
+    virtual bool isHeapObjectAlive(Visitor*) const = 0;
     virtual void trace(Visitor*) { }
 };
 
 template<typename T>
 struct TraceIfNeeded {
     static void trace(Visitor*, T*);
 };
 
 // blink::ScriptWrappable receives special treatment
 // so as to allow it to be used together with GarbageCollected<T>,
 // even when its user-declared destructor is provided.
 // As it is with Oilpan disabled.
 class ScriptWrappable {
 public:
     ~ScriptWrappable() { /* user-declared, thus, non-trivial */ }
 };
 
 }
 
 namespace WTF {
 
 template<typename T>
 struct VectorTraits<blink::Member<T> > {
     static const bool needsDestruction = false;
 };
 
 }
 
 #endif