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 482baef3fa4b62a0c05be194a94163967a4e18cb..c2053a88462ee4ba66b338b016df9d04abf009e0 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);