Use the lock word bits for Baker-style read barrier.

This enables the standard object header to be used with the
Baker-style read barrier.

Bug: 19355854
Bug: 12687968

Change-Id: Ie552b6e1dfe30e96cb1d0895bd0dff25f9d7d015
diff --git a/runtime/mirror/object.h b/runtime/mirror/object.h
index 343c9bc..7f162b7 100644
--- a/runtime/mirror/object.h
+++ b/runtime/mirror/object.h
@@ -62,7 +62,7 @@
 static constexpr bool kCheckFieldAssignments = false;
 
 // Size of Object.
-static constexpr uint32_t kObjectHeaderSize = kUseBakerOrBrooksReadBarrier ? 16 : 8;
+static constexpr uint32_t kObjectHeaderSize = kUseBrooksReadBarrier ? 16 : 8;
 
 // C++ mirror of java.lang.Object
 class MANAGED LOCKABLE Object {
@@ -94,6 +94,9 @@
   NO_RETURN
 #endif
   void SetReadBarrierPointer(Object* rb_ptr) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+#ifndef USE_BAKER_OR_BROOKS_READ_BARRIER
+  NO_RETURN
+#endif
   bool AtomicSetReadBarrierPointer(Object* expected_rb_ptr, Object* rb_ptr)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   void AssertReadBarrierPointer() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
@@ -502,11 +505,11 @@
   // Monitor and hash code information.
   uint32_t monitor_;
 
-#ifdef USE_BAKER_OR_BROOKS_READ_BARRIER
+#ifdef USE_BROOKS_READ_BARRIER
   // Note names use a 'x' prefix and the x_rb_ptr_ is of type int
   // instead of Object to go with the alphabetical/by-type field order
   // on the Java side.
-  uint32_t x_rb_ptr_;      // For the Baker or Brooks pointer.
+  uint32_t x_rb_ptr_;      // For the Brooks pointer.
   uint32_t x_xpadding_;    // For 8-byte alignment. TODO: get rid of this.
 #endif