Make sure that allocation site scratchpad entries get recorded.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/153173008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19268 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -3621,8 +3621,14 @@ void Heap::InitializeAllocationSitesScratchpad() {
 
 void Heap::AddAllocationSiteToScratchpad(AllocationSite* site) {
   if (allocation_sites_scratchpad_length_ < kAllocationSiteScratchpadSize) {
+    // We cannot use the normal write-barrier because slots need to be
+    // recorded with non-incremental marking as well. We have to explicitly
+    // record the slot to take evacuation candidates into account.
     allocation_sites_scratchpad()->set(
-        allocation_sites_scratchpad_length_, site);
+        allocation_sites_scratchpad_length_, site, SKIP_WRITE_BARRIER);
+    Object** slot = allocation_sites_scratchpad()->RawFieldOfElementAt(
+        allocation_sites_scratchpad_length_);
+    mark_compact_collector()->RecordSlot(slot, slot, *slot);
     allocation_sites_scratchpad_length_++;
   }
 }