When adjusting page's live bytes counter from the mutator adjust owners unswept free bytes counter.

src/mark-compact-inl.h

Index: src/mark-compact-inl.h
diff --git a/src/mark-compact-inl.h b/src/mark-compact-inl.h
index 573715e286a2f6a444ebd52e587d4a78157db48b..ae0e61f70165ccbec4719f2b1c44a68eb47a83b4 100644
--- a/src/mark-compact-inl.h
+++ b/src/mark-compact-inl.h
@@ -53,7 +53,7 @@ void MarkCompactCollector::MarkObject(HeapObject* obj, MarkBit mark_bit) {
   ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
   if (!mark_bit.Get()) {
     mark_bit.Set();
-    MemoryChunk::IncrementLiveBytes(obj->address(), obj->Size());
+    MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
     ProcessNewlyMarkedObject(obj);
   }
 }
@@ -63,7 +63,7 @@ void MarkCompactCollector::SetMark(HeapObject* obj, MarkBit mark_bit) {
   ASSERT(!mark_bit.Get());
   ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
   mark_bit.Set();
-  MemoryChunk::IncrementLiveBytes(obj->address(), obj->Size());
+  MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
 }