Move download filename determintion into a separate class.

chrome/browser/download/download_test_file_activity_observer.h

Index: chrome/browser/download/download_test_file_activity_observer.h
diff --git a/chrome/browser/download/download_test_file_activity_observer.h b/chrome/browser/download/download_test_file_activity_observer.h
index 736b9fd005ce26219a8d63b898f90a499dc655eb..760282c8d8e7042214b46e821d7d4ede2b92593f 100644
--- a/chrome/browser/download/download_test_file_activity_observer.h
+++ b/chrome/browser/download/download_test_file_activity_observer.h
@@ -5,7 +5,7 @@
 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_TEST_FILE_ACTIVITY_OBSERVER_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_TEST_FILE_ACTIVITY_OBSERVER_H_
 
-#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 
 class Profile;
 
@@ -32,9 +32,9 @@ class DownloadTestFileActivityObserver {
   bool TestAndResetDidShowFileChooser();
 
  private:
-  class MockDownloadManagerDelegate;
+  class TestDownloadFilePickerFactory;
 
-  scoped_refptr<MockDownloadManagerDelegate> test_delegate_;
+  base::WeakPtr<TestDownloadFilePickerFactory> test_file_picker_factory_;
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_TEST_FILE_ACTIVITY_OBSERVER_H_