Heap profiler: annotate fixed arrays by their purpose.

src/profile-generator.h

Index: src/profile-generator.h
diff --git a/src/profile-generator.h b/src/profile-generator.h
index 6343d057c9628591ac3d0b4163ba6a730ef75cc3..17dd090254e38b26a06dd0d810346fad582de0b6 100644
--- a/src/profile-generator.h
+++ b/src/profile-generator.h
@@ -973,9 +973,13 @@ class V8HeapExplorer : public HeapEntriesAllocator {
   void SetRootShortcutReference(Object* child);
   void SetRootGcRootsReference();
   void SetGcRootsReference(Object* child);
+  bool TagByteArray(Object* maybe_array, const char* tag);
+  bool TagFixedArray(Object* maybe_array, const char* tag);
+  bool TagFixedDoubleArray(Object* maybe_array, const char* tag);
 
   HeapEntry* GetEntry(Object* obj);
 
+  Heap* heap_;
   HeapSnapshot* snapshot_;
   HeapSnapshotsCollection* collection_;
   SnapshottingProgressReportingInterface* progress_;