Teach the Observatory about WeakProperties (ephemerons).

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 19465 matching lines @@
   return reinterpret_cast<RawWeakProperty*>(raw);
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 
 void WeakProperty::PrintJSONImpl(JSONStream* stream, bool ref) const {
-  Instance::PrintJSONImpl(stream, ref);
+  JSONObject jsobj(stream);
+  PrintSharedInstanceJSON(&jsobj, ref);
+  ObjectIdRing* ring = Isolate::Current()->object_id_ring();
+  const intptr_t id = ring->GetIdForObject(raw());
+  jsobj.AddPropertyF("id", "objects/%" Pd "", id);
+
+  if (ref) {
+    return;
+  }
+
+  const Object& key_handle = Object::Handle(key());
+  jsobj.AddProperty("key", key_handle);
+  const Object& value_handle = Object::Handle(value());
+  jsobj.AddProperty("value", value_handle);
 }
 
 RawAbstractType* MirrorReference::GetAbstractTypeReferent() const {
   ASSERT(Object::Handle(referent()).IsAbstractType());
   return AbstractType::Cast(Object::Handle(referent())).raw();
 }
 
 
 RawClass* MirrorReference::GetClassReferent() const {
   ASSERT(Object::Handle(referent()).IsClass());
@@ skipping 189 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart