views/examples: Clean up cpplint warnings.

ui/views/examples/content_client/examples_main_delegate.cc

Index: ui/views/examples/content_client/examples_main_delegate.cc
diff --git a/ui/views/examples/content_client/examples_main_delegate.cc b/ui/views/examples/content_client/examples_main_delegate.cc
index 2cf5cc4739976ae5e7d931021123d7c0739c0221..c9c60ea3319ed37b8d38676760ed1871c4520f34 100644
--- a/ui/views/examples/content_client/examples_main_delegate.cc
+++ b/ui/views/examples/content_client/examples_main_delegate.cc
@@ -4,6 +4,8 @@
 
 #include "ui/views/examples/content_client/examples_main_delegate.h"
 
+#include <string>
+
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/logging.h"
@@ -44,7 +46,7 @@ int ExamplesBrowserMain(
   return exit_code;
 }
 
-}
+}  // namespace
 
 ExamplesMainDelegate::ExamplesMainDelegate() {
 }