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

src/arm/assembler-arm.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 24 matching lines @@
 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 
 // A light-weight ARM Assembler
 // Generates user mode instructions for the ARM architecture up to version 5
 
 #ifndef V8_ARM_ASSEMBLER_ARM_H_
 #define V8_ARM_ASSEMBLER_ARM_H_
 
 #include "assembler.h"
 
-namespace v8 { namespace internal {
+namespace v8 {
+namespace internal {
 
 // CPU Registers.
 //
 // 1) We would prefer to use an enum, but enum values are assignment-
 // compatible with int, which has caused code-generation bugs.
 //
 // 2) We would prefer to use a class instead of a struct but we don't like
 // the register initialization to depend on the particular initialization
 // order (which appears to be different on OS X, Linux, and Windows for the
 // installed versions of C++ we tried). Using a struct permits C-style
@@ skipping 724 matching lines @@
   void link_to(Label* L, Label* appendix);
   void next(Label* L);
 
   // Record reloc info for current pc_
   void RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data = 0);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_