Replace NULL with nullptr in all C++ files.

webrtc/modules/desktop_capture/win/screen_capture_utils.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
 #include "webrtc/modules/desktop_capture/win/screen_capture_utils.h"
 
 #include <windows.h>
 
 #include "webrtc/base/checks.h"
 
 namespace webrtc {
 
 bool GetScreenList(DesktopCapturer::SourceList* screens) {
   RTC_DCHECK(screens->size() == 0);
 
   BOOL enum_result = TRUE;
   for (int device_index = 0;; ++device_index) {
     DISPLAY_DEVICE device;
     device.cb = sizeof(device);
-    enum_result = EnumDisplayDevices(NULL, device_index, &device, 0);
+    enum_result = EnumDisplayDevices(nullptr, device_index, &device, 0);
 
     // |enum_result| is 0 if we have enumerated all devices.
     if (!enum_result)
       break;
 
     // We only care about active displays.
     if (!(device.StateFlags & DISPLAY_DEVICE_ACTIVE))
       continue;
 
     screens->push_back({device_index, std::string()});
   }
   return true;
 }
 
 bool IsScreenValid(DesktopCapturer::SourceId screen, std::wstring* device_key) {
   if (screen == kFullDesktopScreenId) {
     *device_key = L"";
     return true;
   }
 
   DISPLAY_DEVICE device;
   device.cb = sizeof(device);
-  BOOL enum_result = EnumDisplayDevices(NULL, screen, &device, 0);
+  BOOL enum_result = EnumDisplayDevices(nullptr, screen, &device, 0);
   if (enum_result)
     *device_key = device.DeviceKey;
 
   return !!enum_result;
 }
 
 DesktopRect GetScreenRect(DesktopCapturer::SourceId screen,
                           const std::wstring& device_key) {
   if (screen == kFullDesktopScreenId) {
     return DesktopRect::MakeXYWH(GetSystemMetrics(SM_XVIRTUALSCREEN),
                                  GetSystemMetrics(SM_YVIRTUALSCREEN),
                                  GetSystemMetrics(SM_CXVIRTUALSCREEN),
                                  GetSystemMetrics(SM_CYVIRTUALSCREEN));
   }
 
   DISPLAY_DEVICE device;
   device.cb = sizeof(device);
-  BOOL result = EnumDisplayDevices(NULL, screen, &device, 0);
+  BOOL result = EnumDisplayDevices(nullptr, screen, &device, 0);
   if (!result)
     return DesktopRect();
 
   // Verifies the device index still maps to the same display device, to make
   // sure we are capturing the same device when devices are added or removed.
   // DeviceKey is documented as reserved, but it actually contains the registry
   // key for the device and is unique for each monitor, while DeviceID is not.
   if (device_key != device.DeviceKey)
     return DesktopRect();
 
   DEVMODE device_mode;
   device_mode.dmSize = sizeof(device_mode);
   device_mode.dmDriverExtra = 0;
   result = EnumDisplaySettingsEx(
       device.DeviceName, ENUM_CURRENT_SETTINGS, &device_mode, 0);
   if (!result)
     return DesktopRect();
 
   return DesktopRect::MakeXYWH(device_mode.dmPosition.x,
                                device_mode.dmPosition.y,
                                device_mode.dmPelsWidth,
                                device_mode.dmPelsHeight);
 }
 
 }  // namespace webrtc