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

src/spaces.cc

Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index 8c893c07d4f1ed5844f8a9bf1e5c21ea76efead9..1b78e6d5acf30b766e829f659711f5d2395501c1 100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -649,6 +649,17 @@ void MemoryAllocator::ReportStatistics() {
 #endif
 
 // -----------------------------------------------------------------------------
+// MemoryChunk implementation
+
+void MemoryChunk::IncrementLiveBytesFromMutator(Address address, int by) {
+  MemoryChunk* chunk = MemoryChunk::FromAddress(address);
+  if (!chunk->InNewSpace()) {

[Michael Starzinger, 2012/01/18 09:12:18]

We need an additional check here to make sure that the page was elected for lazy
sweeping and isn't just being incrementally marked.

[Vyacheslav Egorov (Chromium), 2012/01/18 09:22:49]

Yeah, thanks for catching it. Somehow I lost this check along the road.

+    static_cast<PagedSpace*>(chunk->owner())->IncrementUnsweptFreeBytes(-by);
+  }
+  chunk->IncrementLiveBytes(by);
+}
+
+// -----------------------------------------------------------------------------
 // PagedSpace implementation
 
 PagedSpace::PagedSpace(Heap* heap,
@@ -2515,7 +2526,7 @@ void LargeObjectSpace::FreeUnmarkedObjects() {
     MarkBit mark_bit = Marking::MarkBitFrom(object);
     if (mark_bit.Get()) {
       mark_bit.Clear();
-      MemoryChunk::IncrementLiveBytes(object->address(), -object->Size());
+      MemoryChunk::IncrementLiveBytesFromGC(object->address(), -object->Size());
       previous = current;
       current = current->next_page();
     } else {