Stop having two URLLoaderFactories in RendererBlinkPlatformImpl

content/renderer/possibly_associated_interface_ptr.h

+// Copyright 2017 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 CONTENT_RENDERER_POSSIBLY_ASSOCIATED_INTERFACE_PTR_H_
+#define CONTENT_RENDERER_POSSIBLY_ASSOCIATED_INTERFACE_PTR_H_
+
+#include "base/macros.h"
+#include "mojo/public/cpp/bindings/associated_interface_ptr.h"
+#include "mojo/public/cpp/bindings/interface_ptr.h"
+
+namespace content {
+
+// PossiblyAssociatedInterfacePtr<T> contains mojo::InterfacePtr<T> or
+// mojo::AssociatedInterfacePtr<T>, but not both. Mojo-related functions in
+// mojo::InterfacePtr<T> and mojo::AssociatedInterfacePtr<T> are not accessible,
+// but a user can access the raw pointer to the interface.
+template <typename T>
+class PossiblyAssociatedInterfacePtr final {
+ public:
+  PossiblyAssociatedInterfacePtr() {}
+  PossiblyAssociatedInterfacePtr(std::nullptr_t) {}
+  PossiblyAssociatedInterfacePtr(mojo::InterfacePtr<T> independent_ptr)
+      : independent_ptr_(std::move(independent_ptr)) {}
+  PossiblyAssociatedInterfacePtr(mojo::AssociatedInterfacePtr<T> associated_ptr)
+      : associated_ptr_(std::move(associated_ptr)) {}
+
+  PossiblyAssociatedInterfacePtr(PossiblyAssociatedInterfacePtr&& other) {
+    independent_ptr_ = std::move(other.independent_ptr_);
+    associated_ptr_ = std::move(other.associated_ptr_);
+  }
+  ~PossiblyAssociatedInterfacePtr() {}
+
+  PossiblyAssociatedInterfacePtr& operator=(
+      PossiblyAssociatedInterfacePtr&& other) {
+    independent_ptr_ = std::move(other.independent_ptr_);
+    associated_ptr_ = std::move(other.associated_ptr_);
+    return *this;
+  }
+
+  T* get() const {
+    return independent_ptr_ ? independent_ptr_.get() : associated_ptr_.get();
+  }
+  T* operator->() const { return get(); }
+  T& operator*() const { return *get(); }
+  explicit operator bool() const { return get(); }
+
+ private:
+  mojo::InterfacePtr<T> independent_ptr_;
+  mojo::AssociatedInterfacePtr<T> associated_ptr_;
+
+  DISALLOW_COPY_AND_ASSIGN(PossiblyAssociatedInterfacePtr);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_POSSIBLY_ASSOCIATED_INTERFACE_PTR_H_