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

mojo/public/cpp/bindings/string_traits_string16.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_STRING_TRAITS_STRING16_H_
 #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;
   }
 
   static void SetToNull(base::string16* output) {
     // Convert null to an "empty" base::string16.
     output->clear();
   }
 
   static void* SetUpContext(const base::string16& input);
   static void TearDownContext(const base::string16& input, void* context);
 
   static size_t GetSize(const base::string16& input, void* context);
   static const char* GetData(const base::string16& input, void* context);
 
   static bool Read(StringDataView input, base::string16* output);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_STRING_TRAITS_STRING16_H_