Keep two empty lines between declarations for cpp files

src/platform-macos.cc

 // Copyright 2012 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 578 matching lines @@
     kMacTlsBaseOffset = 0x60;
 #endif
   } else {
     // 11.x.x (Lion) changed the offset.
     kMacTlsBaseOffset = 0;
   }
 
   Release_Store(&tls_base_offset_initialized, 1);
 }
 
+
 static void CheckFastTls(Thread::LocalStorageKey key) {
   void* expected = reinterpret_cast<void*>(0x1234CAFE);
   Thread::SetThreadLocal(key, expected);
   void* actual = Thread::GetExistingThreadLocal(key);
   if (expected != actual) {
     V8_Fatal(__FILE__, __LINE__,
              "V8 failed to initialize fast TLS on current kernel");
   }
   Thread::SetThreadLocal(key, NULL);
 }
@@ skipping 135 matching lines @@
   limit_mutex = CreateMutex();
 }
 
 
 void OS::TearDown() {
   delete limit_mutex;
 }
 
 
 } }  // namespace v8::internal