Force-setting default browser through policy should not crash.

chrome/browser/browser_process_impl.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/browser_process_impl.h"
 
 #include <map>
 #include <set>
 #include <vector>
 
@@ skipping 664 matching lines @@
 bool BrowserProcessImpl::plugin_finder_disabled() const {
   return *plugin_finder_disabled_pref_;
 }
 
 void BrowserProcessImpl::Observe(int type,
                                  const content::NotificationSource& source,
                                  const content::NotificationDetails& details) {
   if (type == chrome::NOTIFICATION_PREF_CHANGED) {
     std::string* pref = content::Details<std::string>(details).ptr();
     if (*pref == prefs::kDefaultBrowserSettingEnabled) {
-      if (local_state_->GetBoolean(prefs::kDefaultBrowserSettingEnabled))
-        ShellIntegration::SetAsDefaultBrowser();
+      ApplyDefaultBrowserPolicy();
     } else if (*pref == prefs::kDisabledSchemes) {
       ApplyDisabledSchemesPolicy();
     } else if (*pref == prefs::kAllowCrossOriginAuthPrompt) {
       ApplyAllowCrossOriginAuthPromptPolicy();
     }
   } else {
     NOTREACHED();
   }
 }
 
@@ skipping 236 matching lines @@
   browser::RegisterLocalState(local_state_.get());
 
   pref_change_registrar_.Init(local_state_.get());
 
   print_job_manager_->InitOnUIThread(local_state_.get());
 
   // Initialize the notification for the default browser setting policy.
   local_state_->RegisterBooleanPref(prefs::kDefaultBrowserSettingEnabled,
                                     false);
   if (local_state_->IsManagedPreference(prefs::kDefaultBrowserSettingEnabled)) {
-    if (local_state_->GetBoolean(prefs::kDefaultBrowserSettingEnabled))
-      ShellIntegration::SetAsDefaultBrowser();
+    ApplyDefaultBrowserPolicy();
   }
   pref_change_registrar_.Add(prefs::kDefaultBrowserSettingEnabled, this);
 
   // Initialize the preference for the plugin finder policy.
   // This preference is only needed on the IO thread so make it available there.
   local_state_->RegisterBooleanPref(prefs::kDisablePluginFinder, false);
   plugin_finder_disabled_pref_.Init(prefs::kDisablePluginFinder,
                                    local_state_.get(), NULL);
   plugin_finder_disabled_pref_.MoveToThread(BrowserThread::IO);
 
@@ skipping 97 matching lines @@
   const ListValue* scheme_list = local_state_->GetList(prefs::kDisabledSchemes);
   for (ListValue::const_iterator iter = scheme_list->begin();
        iter != scheme_list->end(); ++iter) {
     std::string scheme;
     if ((*iter)->GetAsString(&scheme))
       schemes.insert(scheme);
   }
   ChildProcessSecurityPolicy::GetInstance()->RegisterDisabledSchemes(schemes);
 }
 
+void BrowserProcessImpl::ApplyDefaultBrowserPolicy() {
+  if (local_state_->GetBoolean(prefs::kDefaultBrowserSettingEnabled)) {
+    scoped_refptr<ShellIntegration::DefaultWebClientWorker>
+        set_browser_worker = new ShellIntegration::DefaultBrowserWorker(NULL);
+    set_browser_worker->StartSetAsDefault();
+  }
+}
+
 void BrowserProcessImpl::ApplyAllowCrossOriginAuthPromptPolicy() {
   bool value = local_state()->GetBoolean(prefs::kAllowCrossOriginAuthPrompt);
   resource_dispatcher_host()->set_allow_cross_origin_auth_prompt(value);
 }
 
 // The BrowserProcess object must outlive the file thread so we use traits
 // which don't do any management.
 DISABLE_RUNNABLE_METHOD_REFCOUNT(BrowserProcessImpl);
 
 #if defined(IPC_MESSAGE_LOG_ENABLED)
@@ skipping 84 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartBackgroundInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)