Move creation and ownership of DownloadManager from the embedder to content. This matches all the o…

content/public/browser/download_manager.h

Index: content/public/browser/download_manager.h
===================================================================
--- content/public/browser/download_manager.h	(revision 140592)
+++ content/public/browser/download_manager.h	(working copy)
@@ -60,14 +60,12 @@
 class CONTENT_EXPORT DownloadManager
     : public base::RefCountedThreadSafe<DownloadManager> {
  public:
-  static DownloadManager* Create(
-      DownloadManagerDelegate* delegate,
-      net::NetLog* net_log);
-
   // A method that can be used in tests to ensure that all the internal download
   // classes have no pending downloads.
   static bool EnsureNoPendingDownloadsForTesting();
 
+  virtual void SetDelegate(DownloadManagerDelegate* delegate) = 0;
+
   // Shutdown the download manager. Must be called before destruction.
   virtual void Shutdown() = 0;