Move download stuff from download helper back to TabContents. This is basically a revert of r8576...

content/browser/tab_contents/tab_contents.h

Index: content/browser/tab_contents/tab_contents.h
===================================================================
--- content/browser/tab_contents/tab_contents.h	(revision 92629)
+++ content/browser/tab_contents/tab_contents.h	(working copy)
@@ -37,6 +37,7 @@
 class Rect;
 }
 
+class DownloadItem;
 class Extension;
 class LoadNotificationDetails;
 class Profile;
@@ -342,6 +343,13 @@
 
   // Toolbars and such ---------------------------------------------------------
 
+  // Notifies the delegate that a download is about to be started.
+  // This notification is fired before a local temporary file has been created.
+  bool CanDownload(int request_id);
+
+  // Notifies the delegate that a download started.
+  void OnStartDownload(DownloadItem* download);
+
   // Called when a ConstrainedWindow we own is about to be closed.
   void WillClose(ConstrainedWindow* window);