Add GCTracer metrics for a scavenger GC for DOM wrappers

src/global-handles.h

Index: src/global-handles.h
diff --git a/src/global-handles.h b/src/global-handles.h
index 904c5b568a5e33f7a002320fae39da13ab85b8d4..7808d16a03f6e930829671550c5a7bd56b2c7518 100644
--- a/src/global-handles.h
+++ b/src/global-handles.h
@@ -168,7 +168,8 @@ class GlobalHandles {
 
   // Process pending weak handles.
   // Returns true if next major GC is likely to collect more garbage.
-  bool PostGarbageCollectionProcessing(GarbageCollector collector);
+  bool PostGarbageCollectionProcessing(GarbageCollector collector,
+                                       GCTracer* tracer);
 
   // Iterates over all strong handles.
   void IterateStrongRoots(ObjectVisitor* v);