Run clang-modernize -use-nullptr over src/extensions/.

extensions/renderer/extension_helper.cc

 // Copyright 2014 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 "extensions/renderer/extension_helper.h"
 
 #include "content/public/renderer/render_view.h"
 #include "content/public/renderer/render_view_visitor.h"
 #include "extensions/common/api/messaging/message.h"
 #include "extensions/common/constants.h"
@@ skipping 92 matching lines @@
 }
 
 // static
 content::RenderView* ExtensionHelper::GetBackgroundPage(
     const std::string& extension_id) {
   ViewAccumulator accumulator(extension_id, extension_misc::kUnknownWindowId,
                               VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
   content::RenderView::ForEach(&accumulator);
   CHECK_LE(accumulator.views().size(), 1u);
   if (accumulator.views().size() == 0)
-    return NULL;
+    return nullptr;
   return accumulator.views()[0];
 }
 
 ExtensionHelper::ExtensionHelper(content::RenderView* render_view,
                                  Dispatcher* dispatcher)
     : content::RenderViewObserver(render_view),
       content::RenderViewObserverTracker<ExtensionHelper>(render_view),
       dispatcher_(dispatcher),
       view_type_(VIEW_TYPE_INVALID),
       tab_id_(-1),
@@ skipping 132 matching lines @@
       render_view()->GetWebView()->mainFrame()->mainWorldScriptContext();
   ScriptContext* script_context =
       dispatcher_->script_context_set().GetByV8Context(v8_context);
   if (!script_context)
     return;
   script_context->module_system()->CallModuleMethod("app.window",
                                                     "onAppWindowClosed");
 }
 
 }  // namespace extensions