Drain StoreBufferBlock into store buffer instead of iterating over it directly.

runtime/vm/store_buffer.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_STORE_BUFFER_H_
 #define VM_STORE_BUFFER_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/hash_set.h"
@@ skipping 77 matching lines @@
     DISALLOW_COPY_AND_ASSIGN(DedupSet);
   };
 
   StoreBuffer() : dedup_sets_(new DedupSet(NULL)), count_(1) {}
   ~StoreBuffer();
 
   void Reset();
 
   void AddPointer(uword address);
 
+  // Drain StoreBufferBlock into deduplication sets.
   void ProcessBlock(StoreBufferBlock* block);
 
   DedupSet* DedupSets() {
     DedupSet* result = dedup_sets_;
     dedup_sets_ = new DedupSet(NULL);
     count_ = 1;
     return result;
   }
 
  private:
+  // Add pointer to deduplication sets. Returns true if the current set is full
+  // and a new set was created.
+  bool AddPointerInternal(uword address);
+
   DedupSet* dedup_sets_;
   intptr_t count_;
 
   DISALLOW_COPY_AND_ASSIGN(StoreBuffer);
 };
 
 }  // namespace dart
 
 #endif  // VM_STORE_BUFFER_H_