Add a null check for PermissionBubbleManager::FromWebcontents.

chrome/browser/chrome_quota_permission_context.cc

 // Copyright (c) 2012 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/chrome_quota_permission_context.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/prefs/pref_service.h"
@@ skipping 265 matching lines @@
     // The tab may have gone away or the request may not be from a tab.
     LOG(WARNING) << "Attempt to request quota tabless renderer: "
                  << render_process_id << "," << params.render_view_id;
     DispatchCallbackOnIOThread(callback, QUOTA_PERMISSION_RESPONSE_CANCELLED);
     return;
   }
 
   if (PermissionBubbleManager::Enabled()) {
     PermissionBubbleManager* bubble_manager =
         PermissionBubbleManager::FromWebContents(web_contents);
-    bubble_manager->AddRequest(new QuotaPermissionRequest(this,
-            params.origin_url, params.requested_size, params.user_gesture,
-            Profile::FromBrowserContext(web_contents->GetBrowserContext())->
-                GetPrefs()->GetString(prefs::kAcceptLanguages),
-            callback));
+    if (bubble_manager) {
+      bubble_manager->AddRequest(new QuotaPermissionRequest(this,
+              params.origin_url, params.requested_size, params.user_gesture,
+              Profile::FromBrowserContext(web_contents->GetBrowserContext())->
+                  GetPrefs()->GetString(prefs::kAcceptLanguages),
+              callback));
+    }
     return;
   }
 
   InfoBarService* infobar_service =
       InfoBarService::FromWebContents(web_contents);
   if (!infobar_service) {
     // The tab has no infobar service.
     LOG(WARNING) << "Attempt to request quota from a background page: "
                  << render_process_id << "," << params.render_view_id;
     DispatchCallbackOnIOThread(callback, QUOTA_PERMISSION_RESPONSE_CANCELLED);
@@ skipping 16 matching lines @@
         content::BrowserThread::IO, FROM_HERE,
         base::Bind(&ChromeQuotaPermissionContext::DispatchCallbackOnIOThread,
                    this, callback, response));
     return;
   }
 
   callback.Run(response);
 }
 
 ChromeQuotaPermissionContext::~ChromeQuotaPermissionContext() {}