              'events/EventInit.idl',
              'events/EventListenerOptions.idl',
              'events/EventModifierInit.idl',
-@@ -3835,6 +3840,8 @@
+@@ -3837,6 +3842,8 @@
              '<(blink_core_output_dir)/events/DragEventInit.h',
              '<(blink_core_output_dir)/events/ErrorEventInit.cpp',
              '<(blink_core_output_dir)/events/ErrorEventInit.h',

 
             DCHECK(lifecycle().state() >= DocumentLifecycle::CompositingClean);
diff --git a/third_party/WebKit/Source/core/frame/UseCounter.h b/third_party/WebKit/Source/core/frame/UseCounter.h
index f7c528c..8eb552f 100644
--- a/third_party/WebKit/Source/core/frame/UseCounter.h
+++ b/third_party/WebKit/Source/core/frame/UseCounter.h
@@ -1270,6 +1270,8 @@ public:
         VisualViewportResizeFired = 1466,
         NodeGetRootNode = 1467,
 
+        DocumentCreateEventRequestedVisibilityEvent = 1500,
+

         // numbers of any item, and don't reuse removed slots.
         // Also, run update_use_counter_feature_enum.py in chromium/src/tools/metrics/histograms/
diff --git a/third_party/WebKit/Source/core/layout/LayoutView.cpp b/third_party/WebKit/Source/core/layout/LayoutView.cpp
index 35466da..7d33a0e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutView.cpp
@@ -24,7 +24,9 @@
