Explicitly initialize MarkCompactCollector and ExternalStringTable

src/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 444 matching lines @@
   inline void Iterate(ObjectVisitor* v);
 
   // Restores internal invariant and gets rid of collected strings.
   // Must be called after each Iterate() that modified the strings.
   void CleanUp();
 
   // Destroys all allocated memory.
   void TearDown();
 
  private:
-  ExternalStringTable() { }
+  explicit ExternalStringTable(Heap* heap) : heap_(heap) { }
 
   friend class Heap;
 
   inline void Verify();
 
   inline void AddOldString(String* string);
 
   // Notifies the table that only a prefix of the new list is valid.
   inline void ShrinkNewStrings(int position);
 
@@ skipping 2564 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_