Keep two empty lines between declarations for cpp files

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 15486)
+++ src/heap.cc	(working copy)
@@ -3501,6 +3501,7 @@
   }
 }
 
+
 ExternalArray* Heap::EmptyExternalArrayForMap(Map* map) {
   return ExternalArray::cast(
       roots_[RootIndexForEmptyExternalArray(map->elements_kind())]);
@@ -5231,6 +5232,7 @@
   String::WriteToFlat(s, chars, 0, len);
 }
 
+
 static inline void WriteTwoByteData(String* s, uint16_t* chars, int len) {
   ASSERT(s->length() == len);
   String::WriteToFlat(s, chars, 0, len);
@@ -5415,6 +5417,7 @@
   return result;
 }
 
+
 MaybeObject* Heap::AllocateEmptyExternalArray(ExternalArrayType array_type) {
   return AllocateExternalArray(0, array_type, NULL, TENURED);
 }
@@ -6751,6 +6754,7 @@
   MarkCompactCollector::Initialize();
 }
 
+
 bool Heap::SetUp() {
 #ifdef DEBUG
   allocation_timeout_ = FLAG_gc_interval;
@@ -6861,6 +6865,7 @@
   return true;
 }
 
+
 bool Heap::CreateHeapObjects() {
   // Create initial maps.
   if (!CreateInitialMaps()) return false;
@@ -7026,6 +7031,7 @@
   }
 };
 
+
 void Heap::PrintHandles() {
   PrintF("Handles:\n");
   PrintHandleVisitor v;