Include viewport visibility checks for autoplay experiment.

Source/core/layout/LayoutView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 10 matching lines @@
 #include "config.h"
 #include "core/layout/LayoutView.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/editing/FrameSelection.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/html/HTMLIFrameElement.h"
+#include "core/html/HTMLVideoElement.h"
 #include "core/inspector/InspectorTraceEvents.h"
 #include "core/layout/HitTestResult.h"
 #include "core/layout/LayoutFlowThread.h"
 #include "core/layout/LayoutGeometryMap.h"
+#include "core/layout/LayoutMedia.h"
 #include "core/layout/LayoutPart.h"
 #include "core/layout/LayoutQuote.h"
 #include "core/layout/LayoutScrollbarPart.h"
 #include "core/layout/compositing/DeprecatedPaintLayerCompositor.h"
 #include "core/page/Page.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 #include "core/paint/ViewPainter.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "platform/TraceEvent.h"
 #include "platform/TracedValue.h"
@@ skipping 960 matching lines @@
     float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 void LayoutView::willBeDestroyed()
 {
     LayoutBlockFlow::willBeDestroyed();
     m_compositor.clear();
 }
 
+void LayoutView::registerMediaForPositionChangeNotification(LayoutMedia* media)
+{
+    if (!m_mediaForPositionNotification.contains(media))
+        m_mediaForPositionNotification.append(media);
+}
+
+void LayoutView::unregisterMediaForPositionChangeNotification(LayoutMedia* media)
+{
+    size_t at = m_mediaForPositionNotification.find(media);
+    if (at != kNotFound)
+        m_mediaForPositionNotification.remove(at);
+}
+
+void LayoutView::sendMediaPositionChangeNotifications()
+{
+    for (auto& media : m_mediaForPositionNotification) {
+        media->notifyPositionMayHaveChanged();
+    }
+}
+
 } // namespace blink