Turn //mojo/public/cpp/bindings and //mojo/public/cpp/system into components

mojo/public/cpp/bindings/string_traits_string16.h

Index: mojo/public/cpp/bindings/string_traits_string16.h
diff --git a/mojo/public/cpp/bindings/string_traits_string16.h b/mojo/public/cpp/bindings/string_traits_string16.h
index 5a089080bd0170ee0e5244193ddc47b583362800..f96973ad9145690beb828126975c198bb8ff9f45 100644
--- a/mojo/public/cpp/bindings/string_traits_string16.h
+++ b/mojo/public/cpp/bindings/string_traits_string16.h
@@ -6,12 +6,13 @@
 #define MOJO_PUBLIC_CPP_BINDINGS_STRING_TRAITS_STRING16_H_
 
 #include "base/strings/string16.h"
+#include "mojo/public/cpp/bindings/bindings_export.h"
 #include "mojo/public/cpp/bindings/string_traits.h"
 
 namespace mojo {
 
 template <>
-struct StringTraits<base::string16> {
+struct MOJO_CPP_BINDINGS_EXPORT StringTraits<base::string16> {
   static bool IsNull(const base::string16& input) {
     // base::string16 is always converted to non-null mojom string.
     return false;