Avoid crash in trying to access profile while shutting down.

chrome/browser/ui/browser.cc

 // 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.
 
 #include "chrome/browser/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // OS_WIN
@@ skipping 3886 matching lines @@
       window()->UserChangedTheme();
       break;
 #endif
 
     case chrome::NOTIFICATION_PREF_CHANGED: {
       const std::string& pref_name =
           *content::Details<std::string>(details).ptr();
       if (pref_name == prefs::kPrintingEnabled) {
         UpdatePrintingState(GetContentRestrictionsForSelectedTab());
       } else if (pref_name == prefs::kInstantEnabled) {
-        if (!InstantController::IsEnabled(profile())) {
+        if (browser_shutdown::ShuttingDownWithoutClosingBrowsers() ||

[Jói, 2012/06/11 22:44:47]

Don't you want the inverse condition?

[sreeram, 2012/06/11 22:53:03]

No. If we are shutting down, the first clause returns true, so we don't check
the second clause (which is the one that uses profile and crashes). We'll then
delete the InstantController object, which is fine since we are shutting down.

In the normal case, the first clause returns false, and things behave as before.

+            !InstantController::IsEnabled(profile())) {
           if (instant()) {
             instant()->DestroyPreviewContents();
             instant_.reset();
             instant_unload_handler_.reset();
           }
         } else {
           CreateInstantIfNecessary();
         }
       } else if (pref_name == prefs::kIncognitoModeAvailability) {
         UpdateCommandsForIncognitoAvailability();
@@ skipping 1254 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }