Let store buffer start out small for a 1Mbyte saving in boot

src/heap.cc

 // 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 994 matching lines @@
     start_of_current_page_ = store_buffer_->Top();
     current_page_ = page;
   } else if (event == kStoreBufferFullEvent) {
     // The current page overflowed the store buffer again.  Wipe out its entries
     // in the store buffer and mark it scan-on-scavenge again.  This may happen
     // several times while scanning.
     if (current_page_ == NULL) {
       // Store Buffer overflowed while scanning promoted objects.  These are not
       // in any particular page, though they are likely to be clustered by the
       // allocation routines.
-      store_buffer_->HandleFullness();
+      store_buffer_->EnsureSpace(StoreBuffer::kStoreBufferSize);
     } else {
       // Store Buffer overflowed while scanning a particular old space page for
       // pointers to new space.
       ASSERT(current_page_ == page);
       ASSERT(page != NULL);
       current_page_->set_scan_on_scavenge(true);
       ASSERT(start_of_current_page_ != store_buffer_->Top());
       store_buffer_->SetTop(start_of_current_page_);
     }
   } else {
@@ skipping 5557 matching lines @@
   isolate_->heap()->store_buffer()->Compact();
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal