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

src/spaces.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 13 matching lines @@
 // 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.
 
 #include "v8.h"
 
 #include "macro-assembler.h"
 #include "mark-compact.h"
 #include "platform.h"
 
-namespace v8 { namespace internal {
+namespace v8 {
+namespace internal {
 
 // For contiguous spaces, top should be in the space (or at the end) and limit
 // should be the end of the space.
 #define ASSERT_SEMISPACE_ALLOCATION_INFO(info, space) \
   ASSERT((space).low() <= (info).top                 \
          && (info).top <= (space).high()             \
          && (info).limit == (space).high())
 
 
 // ----------------------------------------------------------------------------
@@ skipping 2562 matching lines @@
                      reinterpret_cast<Object**>(object->address()
                                                 + Page::kObjectAreaSize),
                      allocation_top);
       PrintF("\n");
     }
   }
 }
 #endif  // DEBUG
 
 } }  // namespace v8::internal