Keep two empty lines between declarations for cpp files

test/cctest/test-double.cc

 // Copyright 2006-2008 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 32 matching lines @@
   uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
   CHECK_EQ(3512700564088504e-318, Double(ordered).value());
 
   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
   CHECK_EQ(5e-324, Double(min_double64).value());
 
   uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
   CHECK_EQ(1.7976931348623157e308, Double(max_double64).value());
 }
 
+
 TEST(AsDiyFp) {
   uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
   DiyFp diy_fp = Double(ordered).AsDiyFp();
   CHECK_EQ(0x12 - 0x3FF - 52, diy_fp.e());
   // The 52 mantissa bits, plus the implicit 1 in bit 52 as a UINT64.
   CHECK(V8_2PART_UINT64_C(0x00134567, 89ABCDEF) == diy_fp.f());  // NOLINT
 
   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
   diy_fp = Double(min_double64).AsDiyFp();
   CHECK_EQ(-0x3FF - 52 + 1, diy_fp.e());
@@ skipping 158 matching lines @@
   Double d0(-4e-324);
   Double d1(d0.NextDouble());
   Double d2(d1.NextDouble());
   CHECK_EQ(-0.0, d1.value());
   CHECK_EQ(0.0, d2.value());
   CHECK_EQ(4e-324, d2.NextDouble());
   CHECK_EQ(-1.7976931348623157e308, Double(-V8_INFINITY).NextDouble());
   CHECK_EQ(V8_INFINITY,
            Double(V8_2PART_UINT64_C(0x7fefffff, ffffffff)).NextDouble());
 }