Fix crash in ExtensionService::SetIsIncognitoEnabled.

chrome/browser/extensions/extension_service.cc

 // 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.
 
 #include "chrome/browser/extensions/extension_service.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 1458 matching lines @@
   // if the value changed and the extension is actually enabled, since there is
   // no UI otherwise.
   bool old_enabled = extension_prefs_->IsIncognitoEnabled(extension_id);
   if (enabled == old_enabled)
     return;
 
   extension_prefs_->SetIsIncognitoEnabled(extension_id, enabled);
 
   bool extension_is_enabled = std::find(extensions_.begin(), extensions_.end(),
                                         extension) != extensions_.end();
+
+  // When we reload the extension the ID may be invalidated if we've passed it
+  // by const ref everywhere. Make a copy to be safe.
+  std::string id = extension_id;
   if (extension_is_enabled)
     ReloadExtension(extension->id());
 
   // Reloading the extension invalidates the |extension| pointer.
-  extension = GetInstalledExtension(extension_id);
+  extension = GetInstalledExtension(id);
   if (extension)
     SyncExtensionChangeIfNeeded(*extension);
 }
 
 void ExtensionService::SetAppNotificationSetupDone(
     const std::string& extension_id,
     bool value) {
   const Extension* extension = GetInstalledExtension(extension_id);
   // This method is called when the user sets up app notifications.
   // So it is not expected to be called until the extension is installed.
@@ skipping 997 matching lines @@
 
 ExtensionService::NaClModuleInfoList::iterator
     ExtensionService::FindNaClModule(const GURL& url) {
   for (NaClModuleInfoList::iterator iter = nacl_module_list_.begin();
        iter != nacl_module_list_.end(); ++iter) {
     if (iter->url == url)
       return iter;
   }
   return nacl_module_list_.end();
 }