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

extensions/browser/api/usb/usb_apitest.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 "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/ui/browser.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/test/test_utils.h"
 #include "device/usb/usb_service.h"
 #include "extensions/browser/api/usb/usb_api.h"
@@ skipping 165 matching lines @@
     runner->Run();
   }
 
   void SetUpService() {
     UsbService::SetInstanceForTest(new MockUsbService(mock_device_));
   }
 
   virtual void TearDownOnMainThread() OVERRIDE {
     scoped_refptr<content::MessageLoopRunner> runner =
         new content::MessageLoopRunner;
-    UsbService* service = NULL;
+    UsbService* service = nullptr;
     BrowserThread::PostTaskAndReply(
         BrowserThread::FILE,
         FROM_HERE,
         base::Bind(&UsbService::SetInstanceForTest, service),
         runner->QuitClosure());
     runner->Run();
   }
 
  protected:
   scoped_refptr<MockUsbDeviceHandle> mock_device_handle_;
@@ skipping 66 matching lines @@
       .WillOnce(InvokeUsbTransferCallback<5>(device::USB_TRANSFER_ERROR))
       .WillOnce(InvokeUsbTransferCallback<5>(device::USB_TRANSFER_TIMEOUT));
   EXPECT_CALL(*mock_device_handle_.get(), Close()).Times(AnyNumber());
   ASSERT_TRUE(RunExtensionTest("usb/transfer_failure"));
 }
 
 IN_PROC_BROWSER_TEST_F(UsbApiTest, InvalidLengthTransfer) {
   EXPECT_CALL(*mock_device_handle_.get(), Close()).Times(AnyNumber());
   ASSERT_TRUE(RunExtensionTest("usb/invalid_length_transfer"));
 }