Fix crashes in ExtensionService

chrome/browser/ui/browser.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/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <shellapi.h>
 #include <windows.h>
 #endif  // OS_WIN
@@ skipping 1309 matching lines @@
   browser::NavigateParams params(this, url, location_bar->GetPageTransition());
   params.disposition = open_disposition;
   // Use ADD_INHERIT_OPENER so that all pages opened by the omnibox at least
   // inherit the opener. In some cases the tabstrip will determine the group
   // should be inherited, in which case the group is inherited instead of the
   // opener.
   params.tabstrip_add_types =
       TabStripModel::ADD_FORCE_INDEX | TabStripModel::ADD_INHERIT_OPENER;
   browser::Navigate(&params);
 
-  if (profile_->GetExtensionService()->IsInstalledApp(url)) {
+  // TODO: the ExtensionService should never be NULL, but in some cases it is,
+  // see bug 73768. After it is resolved, the explicit test can go away.
+  ExtensionService* service = profile_->GetExtensionService();
+  if (service && service->IsInstalledApp(url)) {
     UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppLaunchHistogram,
                               extension_misc::APP_LAUNCH_OMNIBOX_LOCATION,
                               extension_misc::APP_LAUNCH_BUCKET_BOUNDARY);
   }
 }
 
 void Browser::Stop() {
   UserMetrics::RecordAction(UserMetricsAction("Stop"), profile_);
   GetSelectedTabContentsWrapper()->tab_contents()->Stop();
 }
@@ skipping 2169 matching lines @@
   preview_contents->controller().CopyStateFromAndPrune(
       &tab_contents->controller());
   // TabStripModel takes ownership of preview_contents.
   TabContentsWrapper* old_contents =
       tab_handler_->GetTabStripModel()->ReplaceTabContentsAt(
           index, preview_contents);
   // InstantUnloadHandler takes ownership of old_contents.
   instant_unload_handler_->RunUnloadListenersOrDestroy(old_contents, index);
 
   GURL url = preview_contents->tab_contents()->GetURL();
-  if (profile_->GetExtensionService()->IsInstalledApp(url)) {
+  // TODO: the ExtensionService should never be NULL, but in some cases it is,
+  // see bug 73768. After it is resolved, the explicit test can go away.
+  ExtensionService* service = profile_->GetExtensionService();
+  if (service && service->IsInstalledApp(url)) {
     UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppLaunchHistogram,
                               extension_misc::APP_LAUNCH_OMNIBOX_INSTANT,
                               extension_misc::APP_LAUNCH_BUCKET_BOUNDARY);
   }
 }
 
 void Browser::SetSuggestedText(const string16& text) {
   window()->GetLocationBar()->SetSuggestedText(text);
 }
 
@@ skipping 857 matching lines @@
     // The page transition below is only for the purpose of inserting the tab.
     browser->AddTab(view_source_contents, PageTransition::LINK);
   }
 
   if (profile_->HasSessionService()) {
     SessionService* session_service = profile_->GetSessionService();
     if (session_service)
       session_service->TabRestored(&view_source_contents->controller(), false);
   }
 }