Use associated interface on DownloadedTempFile

content/browser/loader/downloaded_temp_file_impl.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 CONTENT_BROWSER_LOADER_DOWNLOADED_TEMP_FILE_IMPL_H_
 #define CONTENT_BROWSER_LOADER_DOWNLOADED_TEMP_FILE_IMPL_H_
 
 #include "base/macros.h"
 #include "content/common/content_export.h"
 #include "content/common/url_loader_factory.mojom.h"
 
+namespace mojo {
+class AssociatedGroup;
+}
+
 namespace content {
 
 // DownloadedTempFileImpl is created on the download_to_file mode of resource
 // loading. The instance is held by the client and lives until the client
 // destroys the interface, slightly after the URLLoader is destroyed.
 class CONTENT_EXPORT DownloadedTempFileImpl final
     : public mojom::DownloadedTempFile {
  public:
-  static mojo::InterfacePtr<mojom::DownloadedTempFile> Create(int child_id,
-                                                              int request_id);
+  // Creates a DownloadedTempFileImpl, binds it as a strong associated
+  // interface, and returns the interface ptr info to be passed to the client.
+  // That means:
+  //  * The DownloadedTempFile object created here is essentially owned by the
+  //    client. It keeps alive until the client destroys the other endpoint.
+  //  * The resulting interface is associated to the given |associated_group|,
+  //    all Mojo IPCs messages that share |associated_group| will arrive in a
+  //    sequence.
+  static mojom::DownloadedTempFileAssociatedPtrInfo
+  Create(mojo::AssociatedGroup* associated_group, int child_id, int request_id);
+
+  static mojom::DownloadedTempFilePtr CreateForTesting(int child_id,
+                                                       int request_id);
 
   DownloadedTempFileImpl(int child_id, int request_id);
   ~DownloadedTempFileImpl() override;
 
  private:
   int child_id_;
   int request_id_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadedTempFileImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_DOWNLOADED_TEMP_FILE_IMPL_H_