Fix crashes in ExtensionService

chrome/browser/ui/gtk/bookmark_bar_gtk.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/gtk/bookmark_bar_gtk.h"
 
 #include <vector>
 
 #include "base/metrics/histogram.h"
 #include "base/utf_string_conversions.h"
@@ skipping 91 matching lines @@
       "  ythickness = 0\n"
       "  GtkWidget::focus-padding = 0\n"
       "  GtkContainer::border-width = 0\n"
       "  GtkToolbar::internal-padding = 1\n"
       "  GtkToolbar::shadow-type = GTK_SHADOW_NONE\n"
       "}\n"
       "widget \"*chrome-bookmark-toolbar\" style \"chrome-bookmark-toolbar\"");
 }
 
 void RecordAppLaunch(Profile* profile, GURL url) {
-  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))
     return;
 
   UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppLaunchHistogram,
                             extension_misc::APP_LAUNCH_BOOKMARK_BAR,
                             extension_misc::APP_LAUNCH_BUCKET_BOUNDARY);
 }
 
 }  // namespace
 
 const int BookmarkBarGtk::kBookmarkBarNTPHeight = 57;
@@ skipping 1309 matching lines @@
 
   // Find the GtkWidget* for the actual target button.
   int shift = dir == GTK_MENU_DIR_PARENT ? -1 : 1;
   button_idx = (button_idx + shift + folder_list.size()) % folder_list.size();
   PopupForButton(folder_list[button_idx]);
 }
 
 void BookmarkBarGtk::CloseMenu() {
   current_context_menu_->Cancel();
 }