Keep two empty lines between declarations for cpp files

test/cctest/test-mark-compact.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 292 matching lines @@
 
 static int NumberOfWeakCalls = 0;
 static void WeakPointerCallback(v8::Isolate* isolate,
                                 v8::Persistent<v8::Value>* handle,
                                 void* id) {
   ASSERT(id == reinterpret_cast<void*>(1234));
   NumberOfWeakCalls++;
   handle->Dispose(isolate);
 }
 
+
 TEST(ObjectGroups) {
   FLAG_incremental_marking = false;
   CcTest::InitializeVM();
   GlobalHandles* global_handles = Isolate::Current()->global_handles();
 
   NumberOfWeakCalls = 0;
   v8::HandleScope handle_scope(CcTest::isolate());
 
   Handle<Object> g1s1 =
       global_handles->Create(HEAP->AllocateFixedArray(1)->ToObjectChecked());
@@ skipping 258 matching lines @@
 
 
 TEST(RegressJoinThreadsOnIsolateDeinit) {
   intptr_t size_limit = ShortLivingIsolate() * 2;
   for (int i = 0; i < 10; i++) {
     CHECK_GT(size_limit, ShortLivingIsolate());
   }
 }
 
 #endif  // __linux__ and !USE_SIMULATOR