Change DownloadProcessHandle to be more of an encapsulated class.

chrome/browser/download/download_util.h

Index: chrome/browser/download/download_util.h
diff --git a/chrome/browser/download/download_util.h b/chrome/browser/download/download_util.h
index 3fedb5abfc96b2c1947f8fc5a76c7a05f6ebeca2..b77716b9c5dfba82747c0a8e28c80cfee1dcf932 100644
--- a/chrome/browser/download/download_util.h
+++ b/chrome/browser/download/download_util.h
@@ -248,13 +248,6 @@ void DownloadUrl(const GURL& url,
                  int render_view_id,
                  const content::ResourceContext* context);
 
-// Tells the resource dispatcher host to cancel a download request.
-// Must be called on the IO thread.
-// |process_handle| is passed by value because it is ultimately passed to
-// other threads, and this way we don't have to worry about object lifetimes.
-void CancelDownloadRequest(ResourceDispatcherHost* rdh,
-                           DownloadProcessHandle process_handle);
-
 // Sends a notification on downloads being initiated
 // Must be called on the UI thread.
 void NotifyDownloadInitiated(int render_process_id, int render_view_id);