Add 'address' vm service message that finds heap objects.

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
===================================================================
--- runtime/vm/heap.cc	(revision 34144)
+++ runtime/vm/heap.cc	(working copy)
@@ -162,7 +162,7 @@
 }
 
 
-RawInstructions* Heap::FindObjectInCodeSpace(FindObjectVisitor* visitor) {
+RawInstructions* Heap::FindObjectInCodeSpace(FindObjectVisitor* visitor) const {
   // Only executable pages can have RawInstructions objects.
   RawObject* raw_obj = old_space_->FindObject(visitor, HeapPage::kExecutable);
   ASSERT((raw_obj == Object::null()) ||
@@ -176,6 +176,26 @@
 }
 
 
+RawObject* Heap::FindNewObject(FindObjectVisitor* visitor) const {
+  return new_space_->FindObject(visitor);
+}
+
+
+RawObject* Heap::FindObject(FindObjectVisitor* visitor) const {
+  ASSERT(Isolate::Current()->no_gc_scope_depth() != 0);
+  RawObject* raw_obj = FindNewObject(visitor);
+  if (raw_obj != Object::null()) {
+    return raw_obj;
+  }
+  raw_obj = FindOldObject(visitor);
+  if (raw_obj != Object::null()) {
+    return raw_obj;
+  }
+  raw_obj = FindObjectInCodeSpace(visitor);
+  return raw_obj;
+}
+
+
 void Heap::CollectGarbage(Space space, ApiCallbacks api_callbacks) {
   Isolate* isolate = Isolate::Current();
   bool invoke_api_callbacks = (api_callbacks == kInvokeApiCallbacks);