Enable clang style plugin in webrtc/modules/desktop_capture

webrtc/modules/desktop_capture/mouse_cursor_monitor_mac.mm

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 36 matching lines @@
   [new_image unlockFocus];
   return new_image;
 }
 }  // namespace
 
 class MouseCursorMonitorMac : public MouseCursorMonitor {
  public:
   MouseCursorMonitorMac(const DesktopCaptureOptions& options,
                         CGWindowID window_id,
                         ScreenId screen_id);
-  virtual ~MouseCursorMonitorMac();
+  ~MouseCursorMonitorMac() override;
 
   void Init(Callback* callback, Mode mode) override;
   void Capture() override;
 
  private:
   static void DisplaysReconfiguredCallback(CGDirectDisplayID display,
                                            CGDisplayChangeSummaryFlags flags,
                                            void *user_parameter);
   void DisplaysReconfigured(CGDirectDisplayID display,
                             CGDisplayChangeSummaryFlags flags);
@@ skipping 250 matching lines @@
   return new MouseCursorMonitorMac(options, window, kInvalidScreenId);
 }
 
 MouseCursorMonitor* MouseCursorMonitor::CreateForScreen(
     const DesktopCaptureOptions& options,
     ScreenId screen) {
   return new MouseCursorMonitorMac(options, kCGNullWindowID, screen);
 }
 
 }  // namespace webrtc