Implement progress bar for large objects.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 1af3074f36c48f27c0689d2753ab865f8015447b..30abe6d54ca22cbe76b37f55d06ce8691daa0fbf 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -488,6 +488,7 @@ void MarkCompactCollector::ClearMarkbits() {
     MarkBit mark_bit = Marking::MarkBitFrom(obj);
     mark_bit.Clear();
     mark_bit.Next().Clear();
+    Page::FromAddress(obj->address())->ResetProgressBar();
     Page::FromAddress(obj->address())->ResetLiveBytes();
   }
 }