[api] Remove EmbedderReachableReferenceReporter

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index eb1f08a60942d13f71cbb7b9f0e8ab77dcb14451..f93885863a6d5aa098dc2973fdbc6fe4572aaa7d 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -463,16 +463,6 @@ class WeakCallbackInfo {
 enum class WeakCallbackType { kParameter, kInternalFields, kFinalizer };
 
 /**
- * A reporter class that embedder will use to report reachable references found
- * by EmbedderHeapTracer.
- */
-class V8_EXPORT EmbedderReachableReferenceReporter {
- public:
-  virtual void ReportExternalReference(Value* object) = 0;
-  virtual ~EmbedderReachableReferenceReporter() = default;
-};
-
-/**
  * An object reference that is independent of any handle scope.  Where
  * a Local handle only lives as long as the HandleScope in which it was
  * allocated, a PersistentBase handle remains valid until it is explicitly
@@ -569,18 +559,11 @@ template <class T> class PersistentBase {
   V8_INLINE void ClearWeak() { ClearWeak<void>(); }
 
   /**
-   * Deprecated.
-   * TODO(hlopko): remove once migration to reporter is finished.
-   */
-  V8_INLINE void RegisterExternalReference(Isolate* isolate) const {}
-
-  /**
    * Allows the embedder to tell the v8 garbage collector that a certain object
    * is alive. Only allowed when the embedder is asked to trace its heap by
    * EmbedderHeapTracer.
    */
-  V8_INLINE void RegisterExternalReference(
-      EmbedderReachableReferenceReporter* reporter) const;
+  V8_INLINE void RegisterExternalReference(Isolate* isolate) const;
 
   /**
    * Marks the reference to this object independent. Garbage collector is free
@@ -6169,11 +6152,11 @@ class V8_EXPORT PersistentHandleVisitor {  // NOLINT
 enum class MemoryPressureLevel { kNone, kModerate, kCritical };
 
 /**
- * Interface for tracing through the embedder heap. During the v8 garbage
+ * Interface for tracing through the embedder heap. During a v8 garbage
  * collection, v8 collects hidden fields of all potential wrappers, and at the
  * end of its marking phase iterates the collection and asks the embedder to
- * trace through its heap and use reporter to report each js object reachable
- * from any of the given wrappers.
+ * trace through its heap and use reporter to report each JavaScript object
+ * reachable from any of the given wrappers.
  *
  * Before the first call to the TraceWrappersFrom function TracePrologue will be
  * called. When the garbage collection cycle is finished, TraceEpilogue will be
@@ -6191,30 +6174,26 @@ class V8_EXPORT EmbedderHeapTracer {
   };
 
   /**
-   * V8 will call this method with internal fields of found wrappers. The
-   * embedder is expected to store them in its marking deque and trace
-   * reachable wrappers from them when called through |AdvanceTracing|.
+   * Called by v8 to register internal fields of found wrappers.
+   *
+   * The embedder is expected to store them somewhere and trace reachable
+   * wrappers from them when called through |AdvanceTracing|.
    */
   virtual void RegisterV8References(
       const std::vector<std::pair<void*, void*> >& internal_fields) = 0;
 
   /**
-   * Deprecated.
-   * TODO(hlopko) Remove once the migration to reporter is finished.
-   */
-  virtual void TracePrologue() {}
-
-  /**
-   * V8 will call this method at the beginning of a GC cycle. Embedder is
-   * expected to use EmbedderReachableReferenceReporter for reporting all
-   * reachable v8 objects.
+   * Called at the beginning of a GC cycle.
    */
-  virtual void TracePrologue(EmbedderReachableReferenceReporter* reporter) {}
+  virtual void TracePrologue() = 0;
 
   /**
-   * Embedder is expected to trace its heap starting from wrappers reported by
-   * RegisterV8References method, and use reporter for all reachable wrappers.
-   * Embedder is expected to stop tracing by the given deadline.
+   * Called to to make a tracing step in the embedder.
+   *
+   * The embedder is expected to trace its heap starting from wrappers reported
+   * by RegisterV8References method, and report back all reachable wrappers.
+   * Furthermore, the embedder is expected to stop tracing by the given
+   * deadline.
    *
    * Returns true if there is still work to do.
    */
@@ -6222,22 +6201,25 @@ class V8_EXPORT EmbedderHeapTracer {
                               AdvanceTracingActions actions) = 0;
 
   /**
-   * V8 will call this method at the end of a GC cycle.
+   * Called at the end of a GC cycle.
    *
    * Note that allocation is *not* allowed within |TraceEpilogue|.
    */
   virtual void TraceEpilogue() = 0;
 
   /**
-   * Let embedder know v8 entered final marking pause (no more incremental steps
-   * will follow).
+   * Called upon entering the final marking pause. No more incremental marking
+   * steps will follow this call.
    */
-  virtual void EnterFinalPause() {}
+  virtual void EnterFinalPause() = 0;
 
   /**
-   * Throw away all intermediate data and reset to the initial state.
+   * Called when tracing is aborted.
+   *
+   * The embedder is expected to throw away all intermediate data and reset to
+   * the initial state.
    */
-  virtual void AbortTracing() {}
+  virtual void AbortTracing() = 0;
 
   /**
    * Returns the number of wrappers that are still to be traced by the embedder.
@@ -7550,6 +7532,9 @@ class V8_EXPORT V8 {
                          int* index);
   static Local<Value> GetEternal(Isolate* isolate, int index);
 
+  static void RegisterExternallyReferencedObject(internal::Object** object,
+                                                 internal::Isolate* isolate);
+
   template <class K, class V, class T>
   friend class PersistentValueMapBase;
 
@@ -8620,10 +8605,11 @@ P* PersistentBase<T>::ClearWeak() {
 }
 
 template <class T>
-void PersistentBase<T>::RegisterExternalReference(
-    EmbedderReachableReferenceReporter* reporter) const {
+void PersistentBase<T>::RegisterExternalReference(Isolate* isolate) const {
   if (IsEmpty()) return;
-  reporter->ReportExternalReference(this->val_);
+  V8::RegisterExternallyReferencedObject(
+      reinterpret_cast<internal::Object**>(this->val_),
+      reinterpret_cast<internal::Isolate*>(isolate));
 }
 
 template <class T>