Remove UserGestureUtilizedCallback, it's unused outside of tests

third_party/WebKit/Source/core/loader/NavigationScheduler.cpp

Index: third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
diff --git a/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp b/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
index b0199e0acbd21aeff012b83907817e4977421679..081868b9ea7e2c1b108ee856beb1da30a1e8286c 100644
--- a/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
+++ b/third_party/WebKit/Source/core/loader/NavigationScheduler.cpp
@@ -410,7 +410,7 @@ bool NavigationScheduler::MustReplaceCurrentItem(LocalFrame* target_frame) {
   // create a new back/forward item. See https://webkit.org/b/42861 for the
   // original motivation for this.
   if (!target_frame->GetDocument()->LoadEventFinished() &&
-      !UserGestureIndicator::UtilizeUserGesture())
+      !UserGestureIndicator::ProcessingUserGesture())
     return true;
 
   // Navigation of a subframe during loading of an ancestor frame does not