Use associated interface on DownloadedTempFile

content/browser/loader/downloaded_temp_file_impl.h

Index: content/browser/loader/downloaded_temp_file_impl.h
diff --git a/content/browser/loader/downloaded_temp_file_impl.h b/content/browser/loader/downloaded_temp_file_impl.h
index 833b2cba9a931346aec604759d9d653f62a328b6..b44da1a9dd7d317386cf8f6f8269b78b876db755 100644
--- a/content/browser/loader/downloaded_temp_file_impl.h
+++ b/content/browser/loader/downloaded_temp_file_impl.h
@@ -9,6 +9,10 @@
 #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
@@ -17,8 +21,19 @@ namespace content {
 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 destroyes the other endpoint.

[mmenke, 2016/12/15 16:48:19]

nit: destroys

+  //  * 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;