Mojo C++ bindings: provide data view for all object types.

mojo/public/cpp/bindings/string_data_view.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_DATA_VIEW_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_STRING_DATA_VIEW_H_
+
+#include "mojo/public/cpp/bindings/lib/array_internal.h"
+#include "mojo/public/cpp/bindings/lib/serialization_context.h"
+
+namespace mojo {
+
+// Access to the contents of a serialized string.
+class StringDataView {
+ public:
+  StringDataView() {}
+
+  StringDataView(internal::String_Data* data,
+                 internal::SerializationContext* context)
+      : data_(data) {}
+
+  bool is_null() const { return !data_; }
+
+  const char* storage() const { return data_->storage(); }
+
+  size_t size() const { return data_->size(); }
+
+ private:
+  internal::String_Data* data_ = nullptr;
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_STRING_DATA_VIEW_H_