More of the concurrent copying collector.

Bug: 12687968
Change-Id: I62f70274d47df6d6cab714df95c518b750ce3105
diff --git a/runtime/gc/reference_processor.h b/runtime/gc/reference_processor.h
index 5eb095b..c67fd98 100644
--- a/runtime/gc/reference_processor.h
+++ b/runtime/gc/reference_processor.h
@@ -53,7 +53,7 @@
   // The slow path bool is contained in the reference class object, can only be set once
   // Only allow setting this with mutators suspended so that we can avoid using a lock in the
   // GetReferent fast path as an optimization.
-  void EnableSlowPath() EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void EnableSlowPath() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   // Decode the referent, may block if references are being processed.
   mirror::Object* GetReferent(Thread* self, mirror::Reference* reference)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) LOCKS_EXCLUDED(Locks::reference_processor_lock_);