Get rid of HeapEntry to ID map in heap profile serializer

src/profile-generator.h

Index: src/profile-generator.h
===================================================================
--- src/profile-generator.h	(revision 11244)
+++ src/profile-generator.h	(working copy)
@@ -549,6 +549,8 @@
   void set_retained_size(int value) { retained_size_ = value; }
   int ordered_index() { return ordered_index_; }
   void set_ordered_index(int value) { ordered_index_ = value; }
+  int entry_index() { return entry_index_; }
+  void set_entry_index(int value) { entry_index_ = value; }
 
   Vector<HeapGraphEdge> children() {
     return Vector<HeapGraphEdge>(children_arr(), children_count_); }
@@ -606,6 +608,7 @@
     int ordered_index_;  // Used during dominator tree building.
     int retained_size_;  // At that moment, there is no retained size yet.
   };
+  int entry_index_;
   SnapshotObjectId id_;
   HeapEntry* dominator_;
   HeapSnapshot* snapshot_;
@@ -667,8 +670,6 @@
   void ClearPaint();
   HeapEntry* GetEntryById(SnapshotObjectId id);
   List<HeapEntry*>* GetSortedEntriesList();
-  template<class Visitor>
-  void IterateEntries(Visitor* visitor) { entries_.Iterate(visitor); }
   void SetDominatorsToSelf();
 
   void Print(int max_depth);
@@ -687,7 +688,7 @@
   HeapEntry* gc_subroot_entries_[VisitorSynchronization::kNumberOfSyncTags];
   char* raw_entries_;
   List<HeapEntry*> entries_;
-  bool entries_sorted_;
+  List<HeapEntry*> sorted_entries_;
   size_t raw_entries_size_;
   SnapshotObjectId max_snapshot_js_object_id_;
 
@@ -815,7 +816,7 @@
   HeapEntriesMap();
   ~HeapEntriesMap();
 
-  void AllocateEntries();
+  void AllocateEntries(HeapThing root_object);
   HeapEntry* Map(HeapThing thing);
   void Pair(HeapThing thing, HeapEntriesAllocator* allocator, HeapEntry* entry);
   void CountReference(HeapThing from, HeapThing to,
@@ -842,6 +843,8 @@
     int retainers_count;
   };
 
+  static inline void AllocateHeapEntryForMapEntry(HashMap::Entry* map_entry);
+
   static uint32_t Hash(HeapThing thing) {
     return ComputeIntegerHash(
         static_cast<uint32_t>(reinterpret_cast<uintptr_t>(thing)),
@@ -1122,7 +1125,6 @@
  public:
   explicit HeapSnapshotJSONSerializer(HeapSnapshot* snapshot)
       : snapshot_(snapshot),
-        nodes_(ObjectsMatch),
         strings_(ObjectsMatch),
         next_node_id_(1),
         next_string_id_(1),
@@ -1141,9 +1143,7 @@
         v8::internal::kZeroHashSeed);
   }
 
-  void EnumerateNodes();
   HeapSnapshot* CreateFakeSnapshot();
-  int GetNodeId(HeapEntry* entry);
   int GetStringId(const char* s);
   void SerializeEdge(HeapGraphEdge* edge);
   void SerializeImpl();
@@ -1157,7 +1157,6 @@
   static const int kMaxSerializableSnapshotRawSize;
 
   HeapSnapshot* snapshot_;
-  HashMap nodes_;
   HashMap strings_;
   int next_node_id_;
   int next_string_id_;