Keep two empty lines between declarations for cpp files

src/disassembler.cc

Index: src/disassembler.cc
===================================================================
--- src/disassembler.cc	(revision 15486)
+++ src/disassembler.cc	(working copy)
@@ -360,6 +360,8 @@
 int Disassembler::Decode(Isolate* isolate, FILE* f, byte* begin, byte* end) {
   return 0;
 }
+
+
 void Disassembler::Decode(FILE* f, Code* code) {}
 
 #endif  // ENABLE_DISASSEMBLER