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

content/browser/tab_contents/tab_contents_delegate.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #define CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #pragma once
 
 #include <set>
 #include <string>
@@ skipping 13 matching lines @@
 class Point;
 class Rect;
 class Size;
 }
 
 namespace history {
 class HistoryAddPageArgs;
 }
 
 struct ContextMenuParams;
+class DownloadItem;
 class GURL;
 class HtmlDialogUIDelegate;
 struct NativeWebKeyboardEvent;
 class Profile;
 class RenderViewHost;
 class TabContents;
 
 // Objects implement this interface to get notified about changes in the
 // TabContents and to provide necessary functionality.
 class TabContentsDelegate {
@@ skipping 139 matching lines @@
 
   // Changes the blocked state of the tab at |index|. TabContents are
   // considered blocked while displaying a tab modal dialog. During that time
   // renderer host will ignore any UI interaction within TabContent outside of
   // the currently displaying dialog.
   virtual void SetTabContentBlocked(TabContents* contents, bool blocked);
 
   // Notification that |tab_contents| has gained focus.
   virtual void TabContentsFocused(TabContents* tab_content);
 
+  // Asks the delegate if the given tab can download.
+  virtual bool CanDownload(TabContents* source, int request_id);
+
+  // Notifies the delegate that a download is starting.
+  virtual void OnStartDownload(TabContents* source, DownloadItem* download);
+
   // Return much extra vertical space should be allotted to the
   // render view widget during various animations (e.g. infobar closing).
   // This is used to make painting look smoother.
   virtual int GetExtraRenderViewHeight() const;
 
   // Returns true if the context menu operation was handled by the delegate.
   virtual bool HandleContextMenu(const ContextMenuParams& params);
 
   // Returns true if the context menu command was handled
   virtual bool ExecuteContextMenuCommand(int command);
@@ skipping 89 matching lines @@
   void Attach(TabContents* source);
 
   // Called when |this| is no longer the TabContentsDelegate for |source|.
   void Detach(TabContents* source);
 
   // The TabContents that this is currently a delegate for.
   std::set<TabContents*> attached_contents_;
 };
 
 #endif  // CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_