Rename usesOverlayScrollbars of settings to mockScrollbarsUseOverlay

Source/core/testing/InternalSettings.cpp

Index: Source/core/testing/InternalSettings.cpp
diff --git a/Source/core/testing/InternalSettings.cpp b/Source/core/testing/InternalSettings.cpp
index dc78943a2cebf97d6d13409755b5918e30a7c88a..14be8209511f976a7e2d097f71c323f434d8381e 100644
--- a/Source/core/testing/InternalSettings.cpp
+++ b/Source/core/testing/InternalSettings.cpp
@@ -67,6 +67,7 @@ InternalSettings::Backup::Backup(Settings* settings)
     , m_originalTextAutosizingFontScaleFactor(settings->textAutosizingFontScaleFactor())
     , m_originalMediaTypeOverride(settings->mediaTypeOverride())
     , m_originalMockScrollbarsEnabled(settings->mockScrollbarsEnabled())
+    , m_originalMockScrollbarsUseOverlay(settings->mockScrollbarsUseOverlay())
     , m_langAttributeAwareFormControlUIEnabled(RuntimeEnabledFeatures::langAttributeAwareFormControlUIEnabled())
     , m_imagesEnabled(settings->areImagesEnabled())
     , m_shouldDisplaySubtitles(settings->shouldDisplaySubtitles())
@@ -89,6 +90,7 @@ void InternalSettings::Backup::restoreTo(Settings* settings)
     settings->setTextAutosizingFontScaleFactor(m_originalTextAutosizingFontScaleFactor);
     settings->setMediaTypeOverride(m_originalMediaTypeOverride);
     settings->setMockScrollbarsEnabled(m_originalMockScrollbarsEnabled);
+    settings->setMockScrollbarsUseOverlay(m_originalMockScrollbarsUseOverlay);
     RuntimeEnabledFeatures::setLangAttributeAwareFormControlUIEnabled(m_langAttributeAwareFormControlUIEnabled);
     settings->setImagesEnabled(m_imagesEnabled);
     settings->setShouldDisplaySubtitles(m_shouldDisplaySubtitles);
@@ -161,6 +163,12 @@ void InternalSettings::setMockScrollbarsEnabled(bool enabled, ExceptionState& es
     settings()->setMockScrollbarsEnabled(enabled);
 }
 
+void InternalSettings::setMockScrollbarsUseOverlay(bool enabled, ExceptionState& es)
+{
+    InternalSettingsGuardForSettings();
+    settings()->setMockScrollbarsUseOverlay(enabled);
+}
+
 void InternalSettings::setAuthorShadowDOMForAnyElementEnabled(bool isEnabled)
 {
     RuntimeEnabledFeatures::setAuthorShadowDOMForAnyElementEnabled(isEnabled);