Merge up to 8597 to experimental/gc from the bleeding edge.

src/profile-generator.h

Index: src/profile-generator.h
===================================================================
--- src/profile-generator.h	(revision 8618)
+++ src/profile-generator.h	(working copy)
@@ -641,8 +641,7 @@
 class HeapSnapshot {
  public:
   enum Type {
-    kFull = v8::HeapSnapshot::kFull,
-    kAggregated = v8::HeapSnapshot::kAggregated
+    kFull = v8::HeapSnapshot::kFull
   };
 
   HeapSnapshot(HeapSnapshotsCollection* collection,
@@ -862,6 +861,8 @@
   void Clear();
   bool Contains(Object* object);
   void Insert(Object* obj);
+  const char* GetTag(Object* obj);
+  void SetTag(Object* obj, const char* tag);
 
  private:
   HashMap entries_;
@@ -924,6 +925,7 @@
   int EstimateObjectsCount(HeapIterator* iterator);
   bool IterateAndExtractReferences(HeapIterator* iterator,
                                    SnapshotFillerInterface* filler);
+  void TagGlobalObjects();
 
   static HeapObject* const kInternalRootObject;
 
@@ -975,13 +977,16 @@
   void SetRootShortcutReference(Object* child);
   void SetRootGcRootsReference();
   void SetGcRootsReference(Object* child);
+  void TagObject(Object* obj, const char* tag);
 
   HeapEntry* GetEntry(Object* obj);
 
+  Heap* heap_;
   HeapSnapshot* snapshot_;
   HeapSnapshotsCollection* collection_;
   SnapshottingProgressReportingInterface* progress_;
   SnapshotFillerInterface* filler_;
+  HeapObjectsSet objects_tags_;
 
   static HeapObject* const kGcRootsObject;