Fullscreen Notifications: Fix crash if delegate is NULL

chrome/browser/notifications/fullscreen_notification_blocker.cc

 // Copyright 2013 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/notifications/fullscreen_notification_blocker.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/fullscreen.h"
@@ skipping 53 matching lines @@
 
 void FullscreenNotificationBlocker::CheckState() {
   bool was_fullscreen_mode = is_fullscreen_mode_;
   is_fullscreen_mode_ = DoesFullscreenModeBlockNotifications();
   if (is_fullscreen_mode_ != was_fullscreen_mode)
     NotifyBlockingStateChanged();
 }
 
 bool FullscreenNotificationBlocker::ShouldShowNotificationAsPopup(
     const message_center::Notification& notification) const {
-  bool enabled = !is_fullscreen_mode_ ||
-      notification.delegate()->ShouldDisplayOverFullscreen();
+  bool enabled = !is_fullscreen_mode_;
+  if (is_fullscreen_mode_ && notification.delegate())
+    enabled = notification.delegate()->ShouldDisplayOverFullscreen();
+
 #if defined(USE_ASH)
   if (ash::Shell::HasInstance())
     enabled = enabled || ash::system_notifier::ShouldAlwaysShowPopups(
         notification.notifier_id());
 #endif
 
   if (enabled && !is_fullscreen_mode_) {
     UMA_HISTOGRAM_ENUMERATION("Notifications.Display_Windowed",
                               notification.notifier_id().type,
                               NotifierId::SIZE);
   }
 
   return enabled;
 }
 
 void FullscreenNotificationBlocker::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK_EQ(chrome::NOTIFICATION_FULLSCREEN_CHANGED, type);
   CheckState();
 }