Mojo C++ bindings: introduce mojo::WTFMap for blink bindings.

mojo/public/cpp/bindings/wtf_array.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_WTF_ARRAY_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_WTF_ARRAY_H_
 
 #include <stddef.h>
 #include <utility>
 
@@ skipping 10 matching lines @@
 // mojo::WTFArray is move-only and can be null.
 // It is easy to convert between WTF::Vector<T> and mojo::WTFArray<T>:
 //   - constructor WTFArray(WTF::Vector<T>&&) takes the contents of a
 //     WTF::Vector<T>;
 //   - method PassStorage() passes the underlying WTF::Vector.
 template <typename T>
 class WTFArray {
   MOVE_ONLY_TYPE_FOR_CPP_03(WTFArray);
 
  public:
-  using Data_ = internal::Array_Data<
-      typename internal::GetDataTypeAsArrayElement<T>::Data>;
-  using Element = T;
-
   // Constructs an empty array.
   WTFArray() : is_null_(false) {}
   // Constructs a null array.
   WTFArray(std::nullptr_t null_pointer) : is_null_(true) {}
 
   // Constructs a new non-null array of the specified size. The elements will
   // be value-initialized (meaning that they will be initialized by their
   // default constructor, if any, or else zero-initialized).
   explicit WTFArray(size_t size) : vec_(size), is_null_(false) {}
   ~WTFArray() {}
@@ skipping 153 matching lines @@
     Swap(other);
   }
 
   WTF::Vector<T> vec_;
   bool is_null_;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_WTF_ARRAY_H_