Settings reset prompt: Fix crash when fetching default settings.

chrome/browser/safe_browsing/settings_reset_prompt/settings_reset_prompt_model.cc

 // Copyright 2017 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/safe_browsing/settings_reset_prompt/settings_reset_prompt_model.h"
 
 #include <utility>
 
 #include "base/bind_helpers.h"
 #include "base/callback.h"
@@ skipping 118 matching lines @@
   // For non Google Chrome builds and cases with an empty |brandcode|, we create
   // a default-constructed |BrandcodedDefaultSettings| object and post the
   // callback immediately.
   PostCallbackAndDeleteSelf(base::MakeUnique<BrandcodedDefaultSettings>());
 }
 
 void DefaultSettingsFetcher::OnSettingsFetched() {
   DCHECK(config_fetcher_);
   DCHECK(!config_fetcher_->IsActive());
 
-  PostCallbackAndDeleteSelf(config_fetcher_->GetSettings());
+  std::unique_ptr<BrandcodedDefaultSettings> settings(
+      config_fetcher_->GetSettings());
+  // Use default settings if fetching of BrandcodedDefaultSettings fails.
+  if (!settings)
+    settings.reset(new BrandcodedDefaultSettings());
+
+  PostCallbackAndDeleteSelf(std::move(settings));
 }
 
 void DefaultSettingsFetcher::PostCallbackAndDeleteSelf(
     std::unique_ptr<BrandcodedDefaultSettings> default_settings) {
   DCHECK(default_settings);
   content::BrowserThread::PostTask(
       content::BrowserThread::UI, FROM_HERE,
       base::BindOnce(std::move(callback_), base::Passed(&default_settings)));
   delete this;
 }
@@ skipping 403 matching lines @@
           GetExtension(profile_, extension_id);
       if (extension && management_policy->MustRemainEnabled(extension, nullptr))
         return true;
     }
   }
 
   return false;
 }
 
 }  // namespace safe_browsing.