Handle WebContentsViewMac being destroyed while a <select> menu is showing.

content/browser/web_contents/web_contents_view_mac.mm

 // Copyright (c) 2012 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.
 
 #import <Carbon/Carbon.h>
 
 #import "content/browser/web_contents/web_contents_view_mac.h"
 
 #include <string>
 
@@ skipping 289 matching lines @@
 
 void WebContentsViewMac::ShowPopupMenu(
     RenderFrameHost* render_frame_host,
     const gfx::Rect& bounds,
     int item_height,
     double item_font_size,
     int selected_item,
     const std::vector<MenuItem>& items,
     bool right_aligned,
     bool allow_multiple_selection) {
-  popup_menu_helper_.reset(new PopupMenuHelper(render_frame_host));
+  popup_menu_helper_.reset(new PopupMenuHelper(this, render_frame_host));
   popup_menu_helper_->ShowPopupMenu(bounds, item_height, item_font_size,
                                     selected_item, items, right_aligned,
                                     allow_multiple_selection);
-  popup_menu_helper_.reset();
+  // Note: |this| may be deleted here.
 }
 
 void WebContentsViewMac::HidePopupMenu() {
   if (popup_menu_helper_)
     popup_menu_helper_->Hide();
 }
 
+void WebContentsViewMac::OnMenuClosed() {
+  popup_menu_helper_.reset();
+}
+
 gfx::Rect WebContentsViewMac::GetViewBounds() const {
   // This method is not currently used on mac.
   NOTIMPLEMENTED();
   return gfx::Rect();
 }
 
 void WebContentsViewMac::SetAllowOtherViews(bool allow) {
   if (allow_other_views_ == allow)
     return;
 
@@ skipping 402 matching lines @@
 
 - (void)viewDidHide {
   [self updateWebContentsVisibility];
 }
 
 - (void)viewDidUnhide {
   [self updateWebContentsVisibility];
 }
 
 @end