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

src/scanner.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 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.
 
 #ifndef V8_SCANNER_H_
 #define V8_SCANNER_H_
 
 #include "token.h"
 #include "char-predicates-inl.h"
 
-namespace v8 { namespace internal {
+namespace v8 {
+namespace internal {
 
 
 class UTF8Buffer {
  public:
   UTF8Buffer();
   ~UTF8Buffer();
 
   void AddChar(uc32 c) {
     if (cursor_ <= limit_ &&
         static_cast<unsigned>(c) <= unibrow::Utf8::kMaxOneByteChar) {
@@ skipping 201 matching lines @@
   }
 
   // Decodes a unicode escape-sequence which is part of an identifier.
   // If the escape sequence cannot be decoded the result is kBadRune.
   uc32 ScanIdentifierUnicodeEscape();
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_H_