NewGC: Clear scan-on-scavenge flag from pages that

src/store-buffer.cc

Index: src/store-buffer.cc
===================================================================
--- src/store-buffer.cc	(revision 8396)
+++ src/store-buffer.cc	(working copy)
@@ -608,6 +608,7 @@
     MemoryChunk* chunk;
     while ((chunk = it.next()) != NULL) {
       if (chunk->scan_on_scavenge()) {
+        chunk->set_scan_on_scavenge(false);
         if (callback_ != NULL) {
           (*callback_)(heap_, chunk, kStoreBufferScanningPageEvent);
         }