Replace NULL with nullptr in all C++ files.

webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.cc

Index: webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.cc
diff --git a/webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.cc b/webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.cc
index 5dcbc52a9e9553d87a0cfc18a13b48e7418785fe..ca8bcaa6d8d0a17868415f5ab1d0ec619a679036 100644
--- a/webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.cc
+++ b/webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.cc
@@ -15,9 +15,7 @@
 namespace webrtc {
 
 ScopedPixelBufferObject::ScopedPixelBufferObject()
-    : cgl_context_(NULL),
-      pixel_buffer_object_(0) {
-}
+    : cgl_context_(nullptr), pixel_buffer_object_(0) {}
 
 ScopedPixelBufferObject::~ScopedPixelBufferObject() {
   Release();
@@ -30,14 +28,14 @@ bool ScopedPixelBufferObject::Init(CGLContextObj cgl_context,
   glGenBuffersARB(1, &pixel_buffer_object_);
   if (glGetError() == GL_NO_ERROR) {
     glBindBufferARB(GL_PIXEL_PACK_BUFFER_ARB, pixel_buffer_object_);
-    glBufferDataARB(GL_PIXEL_PACK_BUFFER_ARB, size_in_bytes, NULL,
+    glBufferDataARB(GL_PIXEL_PACK_BUFFER_ARB, size_in_bytes, nullptr,
                     GL_STREAM_READ_ARB);
     glBindBufferARB(GL_PIXEL_PACK_BUFFER_ARB, 0);
     if (glGetError() != GL_NO_ERROR) {
       Release();
     }
   } else {
-    cgl_context_ = NULL;
+    cgl_context_ = nullptr;
     pixel_buffer_object_ = 0;
   }
   return pixel_buffer_object_ != 0;
@@ -47,7 +45,7 @@ void ScopedPixelBufferObject::Release() {
   if (pixel_buffer_object_) {
     CGLContextObj CGL_MACRO_CONTEXT = cgl_context_;
     glDeleteBuffersARB(1, &pixel_buffer_object_);
-    cgl_context_ = NULL;
+    cgl_context_ = nullptr;
     pixel_buffer_object_ = 0;
   }
 }