Add support for constrained windows on os x, based on Avi's GTMWindowSheetController.

chrome/browser/cocoa/download_request_dialog_delegate_mac.h

Index: chrome/browser/cocoa/download_request_dialog_delegate_mac.h
diff --git a/chrome/browser/cocoa/download_request_dialog_delegate_mac.h b/chrome/browser/cocoa/download_request_dialog_delegate_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..f12ae19b8f77a967a26e0a92212a829062fc9949
--- /dev/null
+++ b/chrome/browser/cocoa/download_request_dialog_delegate_mac.h
@@ -0,0 +1,43 @@
+// Copyright (c) 2009 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 CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_DIALOG_DELEGATE_MAC_H_
+#define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_DIALOG_DELEGATE_MAC_H_
+
+#include "base/scoped_nsobject.h"
+#include "base/scoped_ptr.h"
+#include "chrome/browser/cocoa/constrained_window_mac.h"
+#include "chrome/browser/download/download_request_dialog_delegate.h"
+#include "chrome/browser/download/download_request_manager.h"
+
+@class SheetCallback;
+class TabContents;
+
+class DownloadRequestDialogDelegateMac : public DownloadRequestDialogDelegate,
+                                public ConstrainedWindowMacDelegateSystemSheet {
+ public:
+  DownloadRequestDialogDelegateMac(TabContents* tab,
+      DownloadRequestManager::TabDownloadState* host);
+
+  // Implement ConstrainedWindowMacDelegateSystemSheet.
+  virtual void DeleteDelegate();
+
+  // Called when the sheet is done.
+  void SheetDidEnd(int returnCode);
+
+ private:
+  // DownloadRequestDialogDelegate methods.
+  virtual void CloseWindow();
+
+  // The ConstrainedWindow that is hosting our DownloadRequestDialog.
+  ConstrainedWindow* window_;
+
+  // Has a button on the sheet been clicked?
+  bool responded_;
+
+  DISALLOW_COPY_AND_ASSIGN(DownloadRequestDialogDelegateMac);
+};
+
+#endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_DIALOG_DELEGATE_MAC_H_
+