Heap profiler: annotate fixed arrays by their purpose.

This helps understanding what is a particular array for by
just looking at its name.

R=vitalyr@chromium.org

Review URL: http://codereview.chromium.org/7248058

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8494 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/profile-generator.h

@@ -973,9 +973,11 @@ class V8HeapExplorer : public HeapEntriesAllocator {
   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_;