[clang-tidy] Refactor: Move google clang-tidy checks to namespace clang::tidy::google

http://reviews.llvm.org/D7994

Patch by Richard Thomson!

llvm-svn: 231364
diff --git a/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.h b/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.h
index 5b0d001..0c3b69a 100644
--- a/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.h
+++ b/clang-tools-extra/clang-tidy/google/UsingNamespaceDirectiveCheck.h
@@ -14,6 +14,7 @@
 
 namespace clang {
 namespace tidy {
+namespace google {
 namespace build {
 
 /// \brief Finds using namespace directives.
@@ -29,6 +30,7 @@
 };
 
 } // namespace build
+} // namespace google
 } // namespace tidy
 } // namespace clang