Disable and remove finger.

Finger is useless for multithreaded GC, removing it should provide a
slight speed up due to avoided comparison.

Change-Id: I7eb7abcbab8d3307807b1086c06d68b2d4bcd2e9
diff --git a/runtime/gc/accounting/card_table-inl.h b/runtime/gc/accounting/card_table-inl.h
index f8f2773..fb0f61b 100644
--- a/runtime/gc/accounting/card_table-inl.h
+++ b/runtime/gc/accounting/card_table-inl.h
@@ -41,10 +41,9 @@
   return success;
 }
 
-template <typename Visitor, typename FingerVisitor>
+template <typename Visitor>
 inline void CardTable::Scan(SpaceBitmap* bitmap, byte* scan_begin, byte* scan_end,
-                            const Visitor& visitor, const FingerVisitor& finger_visitor,
-                            const byte minimum_age) const {
+                            const Visitor& visitor, const byte minimum_age) const {
   DCHECK(bitmap->HasAddress(scan_begin));
   DCHECK(bitmap->HasAddress(scan_end - 1));  // scan_end is the byte after the last byte we scan.
   byte* card_cur = CardFromAddr(scan_begin);
@@ -57,7 +56,7 @@
     if (*card_cur >= minimum_age) {
       uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(card_cur));
       uintptr_t end = start + kCardSize;
-      bitmap->VisitMarkedRange(start, end, visitor, finger_visitor);
+      bitmap->VisitMarkedRange(start, end, visitor);
     }
     ++card_cur;
   }
@@ -87,7 +86,7 @@
         << "card " << static_cast<size_t>(card_byte) << " word " << (start_word & 0xFF);
         uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(card));
         uintptr_t end = start + kCardSize;
-        bitmap->VisitMarkedRange(start, end, visitor, finger_visitor);
+        bitmap->VisitMarkedRange(start, end, visitor);
       }
       start_word >>= 8;
     }
@@ -100,7 +99,7 @@
     if (*card_cur >= minimum_age) {
       uintptr_t start = reinterpret_cast<uintptr_t>(AddrFromCard(card_cur));
       uintptr_t end = start + kCardSize;
-      bitmap->VisitMarkedRange(start, end, visitor, finger_visitor);
+      bitmap->VisitMarkedRange(start, end, visitor);
     }
     ++card_cur;
   }