Split nested namespaces declaration in two lines in accordance with C++ Style Guide.

src/serialize.h

 // 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 12 matching lines @@
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_SERIALIZE_H_
 #define V8_SERIALIZE_H_
 
 #include "hashmap.h"
 
-namespace v8 { namespace internal {
+namespace v8 {
+namespace internal {
 
 // A TypeCode is used to distinguish different kinds of external reference.
 // It is a single bit to make testing for types easy.
 enum TypeCode {
   UNCLASSIFIED,        // One-of-a-kind references.
   BUILTIN,
   RUNTIME_FUNCTION,
   IC_UTILITY,
   DEBUG_ADDRESS,
   STATS_COUNTER,
@@ skipping 288 matching lines @@
 #ifdef DEBUG
   bool expect_debug_information_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(Deserializer);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SERIALIZE_H_