Add "isolate" argument to LOG macro to avoid TLS fetches.

src/global-handles.h

 // Copyright 2007-2008 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 127 matching lines @@
 
   // Returns the object groups.
   List<ObjectGroup*>* object_groups() { return &object_groups_; }
 
   // Remove bags, this should only happen after GC.
   void RemoveObjectGroups();
 
   // Tear down the global handle structure.
   void TearDown();
 
+  Isolate* isolate() { return isolate_; }
+
 #ifdef DEBUG
   void PrintStats();
   void Print();
 #endif
   class Pool;
  private:
   explicit GlobalHandles(Isolate* isolate);
 
   // Internal node structure, one for each global handle.
   class Node;
@@ skipping 41 matching lines @@
 
   friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(GlobalHandles);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBAL_HANDLES_H_