Rollback of r18029 in bleeding_edge branch.

src/x64/macro-assembler-x64.cc

 // 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 387 matching lines @@
   }
 
   if (emit_debug_code()) {
     Label ok;
     cmpq(value, Operand(address, 0));
     j(equal, &ok, Label::kNear);
     int3();
     bind(&ok);
   }
 
-  // Count number of write barriers in generated code.
-  isolate()->counters()->write_barriers_static()->Increment();
-  IncrementCounter(isolate()->counters()->write_barriers_dynamic(), 1);
-
   // First, check if a write barrier is even needed. The tests below
   // catch stores of smis and stores into the young generation.
   Label done;
 
   if (smi_check == INLINE_SMI_CHECK) {
     // Skip barrier if writing a smi.
     JumpIfSmi(value, &done);
   }
 
   CheckPageFlag(value,
@@ skipping 4633 matching lines @@
   j(equal, found);
   movq(current, FieldOperand(current, Map::kPrototypeOffset));
   CompareRoot(current, Heap::kNullValueRootIndex);
   j(not_equal, &loop_again);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64