Remove unused ModalDialogDelegate class.

chrome/browser/ui/views/modal_dialog_delegate.cc

-// Copyright (c) 2010 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.
-
-#include "chrome/browser/views/modal_dialog_delegate.h"
-
-#include "base/logging.h"
-#include "chrome/browser/views/window.h"
-#include "views/window/window.h"
-
-void ModalDialogDelegate::ShowModalDialog() {
-  gfx::NativeWindow root_hwnd = GetDialogRootWindow();
-  // GetMessageBoxRootWindow() will be NULL if there's no selected tab (e.g.,
-  // during shutdown), in which case we simply skip showing this dialog.
-  if (!root_hwnd) {
-    Cancel();
-  } else {
-    dialog_ = browser::CreateViewsWindow(root_hwnd, gfx::Rect(), this);
-    dialog_->Show();
-  }
-}
-
-void ModalDialogDelegate::ActivateModalDialog() {
-  DCHECK(dialog_);
-  // Ensure that the dialog is visible and at the top of the z-order. These
-  // conditions may not be true if the dialog was opened on a different virtual
-  // desktop to the one the browser window is on.
-  dialog_->Show();
-  dialog_->Activate();
-}
-
-void ModalDialogDelegate::CloseModalDialog() {
-  // If the dialog is visible close it.
-  if (dialog_)
-    dialog_->Close();
-}
-
-ModalDialogDelegate::ModalDialogDelegate() : dialog_(NULL) {
-}
-