Replace the DownloadFileManager with direct ownership

content/browser/download/mock_download_file.cc

Index: content/browser/download/mock_download_file.cc
diff --git a/content/browser/download/mock_download_file.cc b/content/browser/download/mock_download_file.cc
index d5c7781c9edcd72ac58053637c7f0ba789efc370..9d023722f7d4afebd9e9af653173ab6f4e149bff 100644
--- a/content/browser/download/mock_download_file.cc
+++ b/content/browser/download/mock_download_file.cc
@@ -7,11 +7,19 @@
 using ::testing::_;
 using ::testing::Return;
 
+namespace {
+
+void SuccessRun(content::DownloadFile::InitializeCallback callback) {
+  callback.Run(content::DOWNLOAD_INTERRUPT_REASON_NONE);
+}
+
+}  // namespace
+
 MockDownloadFile::MockDownloadFile() {
   // This is here because |Initialize()| is normally called right after
   // construction.
-  ON_CALL(*this, Initialize())
-      .WillByDefault(Return(content::DOWNLOAD_INTERRUPT_REASON_NONE));
+  ON_CALL(*this, Initialize(_))
+      .WillByDefault(::testing::Invoke(SuccessRun));
 }
 
 MockDownloadFile::~MockDownloadFile() {