Create a very simple TabContentsView (and not fully implemented yet) and add more supporting code...

content/browser/download/download_manager_delegate.h

Index: content/browser/download/download_manager_delegate.h
===================================================================
--- content/browser/download/download_manager_delegate.h	(revision 100929)
+++ content/browser/download/download_manager_delegate.h	(working copy)
@@ -18,6 +18,8 @@
 // Browser's download manager: manages all downloads and destination view.
 class DownloadManagerDelegate {
  public:
+  virtual ~DownloadManagerDelegate() {}
+
   // Lets the delegate know that the download manager is shutting down.
   virtual void Shutdown() = 0;
 
@@ -100,7 +102,6 @@
 
  protected:
   DownloadManagerDelegate() {}
-  virtual ~DownloadManagerDelegate() {}
 
   DISALLOW_COPY_AND_ASSIGN(DownloadManagerDelegate);
 };