Keep two empty lines between declarations for cpp files

src/spaces.cc

Index: src/spaces.cc
===================================================================
--- src/spaces.cc	(revision 15486)
+++ src/spaces.cc	(working copy)
@@ -914,6 +914,7 @@
   chunk->IncrementLiveBytes(by);
 }
 
+
 // -----------------------------------------------------------------------------
 // PagedSpace implementation
 
@@ -994,6 +995,7 @@
   return Failure::Exception();
 }
 
+
 bool PagedSpace::CanExpand() {
   ASSERT(max_capacity_ % AreaSize() == 0);
 
@@ -1868,6 +1870,7 @@
   }
 }
 
+
 // Because the copying collector does not touch garbage objects, we iterate
 // the new space before a collection to get a histogram of allocated objects.
 // This only happens when --log-gc flag is set.
@@ -1961,6 +1964,7 @@
   return size;
 }
 
+
 // -----------------------------------------------------------------------------
 // Free lists for old object spaces implementation