Everywhere: Use 'decrease_slider_by()' method from AbstractSlider

The same idea as 'increase_slider_by()', it helps us to avoid repeating
the pattern 'set_value(value() - delta)'.

1 files changed, 1 insertions, 1 deletions

diff --git a/Userland/Applications/PDFViewer/PDFViewer.cpp b/Userland/Applications/PDFViewer/PDFViewer.cpp
index 57ff4ab869..f377466ca8 100644
--- a/Userland/Applications/PDFViewer/PDFViewer.cpp
+++ b/Userland/Applications/PDFViewer/PDFViewer.cpp
@@ -106,7 +106,7 @@ void PDFViewer::mousewheel_event(GUI::MouseEvent& event)
                     scrollbar.set_value(scrollbar.max());
                 }
             } else {
-                scrollbar.set_value(scrollbar.value() - 20);
+                scrollbar.decrease_slider_by(20);
             }
         }
     }