Allow collection of DOM objects in minor GC cycles.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 042f03cf5c3e0c6a183842fd8149337cdd5d3225..d33a19306b158fa081b754c32db424713d2cf698 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -648,6 +648,13 @@ void V8::MarkIndependent(i::Object** object) {
 }
 
 
+void V8::MarkExternallyUnreachable(i::Object** object) {
+  i::Isolate* isolate = i::Isolate::Current();
+  LOG_API(isolate, "MarkExternallyUnreachable");
+  isolate->global_handles()->MarkExternallyUnreachable(object);
+}
+
+
 bool V8::IsGlobalIndependent(i::Object** obj) {
   i::Isolate* isolate = i::Isolate::Current();
   LOG_API(isolate, "IsGlobalIndependent");