[clang-tidy] Cleanup namespace in utils folder.

Summary:
This is a step forward cleaning up the namespaces in clang-tidy/utils.
There is no behavior change.

Reviewers: alexfh

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D19819

llvm-svn: 268356
diff --git a/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp b/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp
index 239c0f7..f80661d 100644
--- a/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp
+++ b/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp
@@ -11,7 +11,8 @@
 
 namespace clang {
 namespace tidy {
-namespace lexer_utils {
+namespace utils {
+namespace lexer {
 
 Token getPreviousNonCommentToken(const ASTContext &Context,
                                  SourceLocation Location) {
@@ -34,6 +35,7 @@
   return Token;
 }
 
-} // namespace lexer_utils
+} // namespace lexer
+} // namespace utils
 } // namespace tidy
 } // namespace clang