Mojo C++ bindings: expose public <struct>DataView and StringDataView.

mojo/public/cpp/bindings/lib/string_traits_wtf.cc

Index: mojo/public/cpp/bindings/lib/string_traits_wtf.cc
diff --git a/mojo/public/cpp/bindings/lib/string_traits_wtf.cc b/mojo/public/cpp/bindings/lib/string_traits_wtf.cc
index 557c28908cd5389d7e9dc1037b29c05ae49e7f27..401a7b7a6bd8e0d9862f346aac3d266305f136a7 100644
--- a/mojo/public/cpp/bindings/lib/string_traits_wtf.cc
+++ b/mojo/public/cpp/bindings/lib/string_traits_wtf.cc
@@ -66,10 +66,10 @@ const char* StringTraits<WTF::String>::GetData(const WTF::String& input,
 }
 
 // static
-bool StringTraits<WTF::String>::Read(internal::String_Data* input,
+bool StringTraits<WTF::String>::Read(StringDataView input,
                                      WTF::String* output) {
-  if (input) {
-    WTF::String result = WTF::String::fromUTF8(input->storage(), input->size());
+  if (!input.is_null()) {
+    WTF::String result = WTF::String::fromUTF8(input.storage(), input.size());
     output->swap(result);
   } else if (!output->isNull()) {
     WTF::String result;