Make the support code for read barriers a bit more general.

Add an option for Baker in addition to Brooks.

Bug: 12687968
Change-Id: I8a31db817ff6686c72951b6534f588228e270b11
diff --git a/runtime/gc/space/image_space.cc b/runtime/gc/space/image_space.cc
index bb52c66..9a2815a 100644
--- a/runtime/gc/space/image_space.cc
+++ b/runtime/gc/space/image_space.cc
@@ -166,10 +166,8 @@
     mirror::Object* obj = reinterpret_cast<mirror::Object*>(current);
     CHECK(live_bitmap_->Test(obj));
     CHECK(obj->GetClass() != nullptr) << "Image object at address " << obj << " has null class";
-    if (kUseBrooksPointer) {
-      CHECK(obj->GetBrooksPointer() == obj)
-          << "Bad Brooks pointer: obj=" << reinterpret_cast<void*>(obj)
-          << " brooks_ptr=" << reinterpret_cast<void*>(obj->GetBrooksPointer());
+    if (kUseBakerOrBrooksReadBarrier) {
+      obj->AssertReadBarrierPointer();
     }
     current += RoundUp(obj->SizeOf(), kObjectAlignment);
   }