Make content_shell handle renderers going away. I've made TabContents call TabContentsView::OnTab...

chrome/browser/tab_contents/tab_contents_view_mac.mm

 // 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.
 
 #import <Carbon/Carbon.h>
 
 #include "chrome/browser/tab_contents/tab_contents_view_mac.h"
 
 #include <string>
 
+#include "chrome/browser/browser_shutdown.h"
 #import "chrome/browser/renderer_host/chrome_render_widget_host_view_mac_delegate.h"
 #include "chrome/browser/tab_contents/popup_menu_helper_mac.h"
 #include "chrome/browser/tab_contents/render_view_context_menu_mac.h"
 #import "chrome/browser/ui/cocoa/focus_tracker.h"
 #import "chrome/browser/ui/cocoa/tab_contents/sad_tab_controller.h"
 #import "chrome/browser/ui/cocoa/tab_contents/web_drag_source.h"
 #import "chrome/browser/ui/cocoa/tab_contents/web_drop_target.h"
 #import "chrome/browser/ui/cocoa/view_id_util.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/renderer_host/render_view_host_factory.h"
@@ skipping 155 matching lines @@
   // when the "zoom" button in the browser window is clicked.
   host->EnablePreferredSizeMode(kPreferredSizeWidth);
 }
 
 void TabContentsViewMac::SetPageTitle(const string16& title) {
   // Meaningless on the Mac; widgets don't have a "title" attribute
 }
 
 void TabContentsViewMac::OnTabCrashed(base::TerminationStatus /* status */,
                                       int /* error_code */) {
+  // Only show the sad tab if we're not in browser shutdown, so that TabContents
+  // objects that are not in a browser (e.g., HTML dialogs) and thus are
+  // visible do not flash a sad tab page.
+  if (browser_shutdown::GetShutdownType() != browser_shutdown::NOT_VALID)
+    return;
+
   if (!sad_tab_.get()) {
     DCHECK(tab_contents_);
     if (tab_contents_) {
       SadTabController* sad_tab =
           [[SadTabController alloc] initWithTabContents:tab_contents_
                                               superview:cocoa_view_];
       sad_tab_.reset(sad_tab);
     }
   }
 }
@@ skipping 380 matching lines @@
       [[[notification userInfo] objectForKey:kSelectionDirection]
         unsignedIntegerValue];
   if (direction == NSDirectSelection)
     return;
 
   [self tabContents]->
       FocusThroughTabTraversal(direction == NSSelectingPrevious);
 }
 
 @end