Fix issues when changing FLAG_concurrent_recompilation after init.

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 1888 matching lines @@
     object_sizes_[FIRST_FIXED_ARRAY_SUB_TYPE + array_sub_type] += size;
   }
 
   void CheckpointObjectStats();
 
   // We don't use a LockGuard here since we want to lock the heap
   // only when FLAG_concurrent_recompilation is true.
   class RelocationLock {
    public:
     explicit RelocationLock(Heap* heap) : heap_(heap) {
-      if (FLAG_concurrent_recompilation) {
-        heap_->relocation_mutex_->Lock();
-      }
+      heap_->relocation_mutex_.Lock();
     }
 
 
     ~RelocationLock() {
-      if (FLAG_concurrent_recompilation) {
-        heap_->relocation_mutex_->Unlock();
-      }
+      heap_->relocation_mutex_.Unlock();
     }
 
    private:
     Heap* heap_;
   };
 
   MaybeObject* AddWeakObjectToCodeDependency(Object* obj, DependentCode* dep);
 
   DependentCode* LookupWeakObjectToCodeDependency(Object* obj);
 
@@ skipping 582 matching lines @@
   // Flag is set when the heap has been configured.  The heap can be repeatedly
   // configured through the API until it is set up.
   bool configured_;
 
   ExternalStringTable external_string_table_;
 
   VisitorDispatchTable<ScavengingCallback> scavenging_visitors_table_;
 
   MemoryChunk* chunks_queued_for_free_;
 
-  Mutex* relocation_mutex_;
+  Mutex relocation_mutex_;
 
   int gc_callbacks_depth_;
 
   friend class Factory;
   friend class GCTracer;
   friend class AlwaysAllocateScope;
   friend class Page;
   friend class Isolate;
   friend class MarkCompactCollector;
   friend class MarkCompactMarkingVisitor;
@@ skipping 596 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_