[heap] Two minor fixes in EstimatedSize

src/context-measure.cc

Index: src/context-measure.cc
diff --git a/src/context-measure.cc b/src/context-measure.cc
index 00c11eebc2cf40a548d16270c4173242f0e78322..a2bcae29853f45e5509322cd45e560d50be8b913 100644
--- a/src/context-measure.cc
+++ b/src/context-measure.cc
@@ -19,6 +19,8 @@ ContextMeasure::ContextMeasure(Context* context)
       size_(0) {
   DCHECK(context_->IsNativeContext());
   Object* next_link = context_->next_context_link();
+  context_->set(Context::NEXT_CONTEXT_LINK,
+                context->GetIsolate()->heap()->undefined_value());
   MeasureObject(context_);
   MeasureDeferredObjects();
   context_->set(Context::NEXT_CONTEXT_LINK, next_link);
@@ -32,6 +34,7 @@ bool ContextMeasure::IsShared(HeapObject* object) {
   if (object->IsCode() && !Code::cast(object)->is_optimized_code()) return true;
   if (object->IsAccessorInfo()) return true;
   if (object->IsWeakCell()) return true;
+  if (object->IsMap()) return true;

[Yang, 2017/03/28 12:11:36]

This is not the right thing to do. Most maps actually belong to a context. Maybe
you can use the logic also used in JSReceiver::GetCreationContext?

[Dan Ehrenberg, 2017/03/28 16:51:06]

Sorry for my confusion; of course they do. The new logic uses GetCreationContext
and only charges objects to the ContextMeasure if they were created in the same
context.

   return false;
 }