Guard against rare case of allocation failure during evacuation.

src/spaces.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1474 matching lines @@
              static_cast<int>(sizes[3]),
              static_cast<double>(sizes[3] * 100) / Page::kObjectAreaSize,
              (ratio > ratio_threshold) ? "[fragmented]" : "");
     }
 
     return (ratio > ratio_threshold) || FLAG_always_compact;
   }
 
   void EvictEvacuationCandidatesFromFreeLists();
 
+  bool CanExpand();
+
  protected:
   // Maximum capacity of this space.
   intptr_t max_capacity_;
 
   // Accounting information for this space.
   AllocationStats accounting_stats_;
 
   // The dummy page that anchors the double linked list of pages.
   Page anchor_;
 
@@ skipping 1010 matching lines @@
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SPACES_H_