Use intersection observer to control frame throttling

third_party/WebKit/Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@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
@@ skipping 10 matching lines @@
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #ifndef FrameView_h
 #define FrameView_h
 
 #include "core/CoreExport.h"
 #include "core/dom/DocumentLifecycle.h"
+#include "core/dom/IntersectionObserverCallback.h"
 #include "core/frame/FrameViewAutoSizeInfo.h"
 #include "core/frame/LayoutSubtreeRootList.h"
 #include "core/frame/RootFrameViewport.h"
 #include "core/layout/ScrollAnchor.h"
 #include "core/paint/FirstMeaningfulPaintDetector.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintInvalidationCapableScrollableArea.h"
 #include "core/paint/PaintPhase.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/Widget.h"
@@ skipping 622 matching lines @@
 
   LayoutAnalyzer* layoutAnalyzer() { return m_analyzer.get(); }
 
   // Returns true if this frame should not render or schedule visual updates.
   bool shouldThrottleRendering() const;
 
   // Returns true if this frame could potentially skip rendering and avoid
   // scheduling visual updates.
   bool canThrottleRendering() const;
   bool isHiddenForThrottling() const { return m_hiddenForThrottling; }
+  void setupRenderThrottling();
 
   // For testing, run pending intersection observer notifications for this
   // frame.
-  void notifyRenderThrottlingObserversForTesting();
+  void updateRenderThrottlingStatusForTesting();
 
   // Paint properties for SPv2 Only.
   void setPreTranslation(
       PassRefPtr<TransformPaintPropertyNode> preTranslation) {
     m_preTranslation = preTranslation;
   }
   TransformPaintPropertyNode* preTranslation() const {
     return m_preTranslation.get();
   }
 
@@ skipping 79 matching lines @@
         : m_scope(&view->m_inUpdateScrollbars, true) {}
 
    private:
     AutoReset<bool> m_scope;
   };
 
   // Only for LayoutPart to traverse into sub frames during paint invalidation.
   void invalidateTreeIfNeeded(const PaintInvalidationState&);
 
  private:
+  class IntersectionObserverCallback
+      : public blink::IntersectionObserverCallback {
+   public:
+    IntersectionObserverCallback(FrameView*, ExecutionContext*);
+
+    // IntersectionObserverCallback implementation:
+    void handleEvent(const HeapVector<Member<IntersectionObserverEntry>>&,
+                     IntersectionObserver&) override;
+    ExecutionContext* getExecutionContext() const override;
+
+    DECLARE_TRACE();
+
+   private:
+    WeakMember<FrameView> m_frameView;
+    WeakMember<ExecutionContext> m_context;
+  };
+
   explicit FrameView(LocalFrame*);
 
   void updateScrollOffset(const ScrollOffset&, ScrollType) override;
 
   void updateLifecyclePhasesInternal(
       DocumentLifecycle::LifecycleState targetState);
 
   void invalidateTreeIfNeededRecursive();
   void scrollContentsIfNeededRecursive();
   void updateStyleAndLayoutIfNeededRecursive();
@@ skipping 104 matching lines @@
 
   void collectAnnotatedRegions(LayoutObject&,
                                Vector<AnnotatedRegionValue>&) const;
 
   template <typename Function>
   void forAllNonThrottledFrameViews(const Function&);
 
   void setNeedsUpdateViewportIntersection();
   void updateViewportIntersectionsForSubtree(
       DocumentLifecycle::LifecycleState targetState);
-  void updateViewportIntersectionIfNeeded();
-  void notifyRenderThrottlingObservers();
-  void updateThrottlingStatus();
+  void updateRenderThrottlingStatus(bool hidden, bool subtreeThrottled);
   void notifyResizeObservers();
 
   // PaintInvalidationCapableScrollableArea
   LayoutScrollbarPart* resizer() const override { return nullptr; }
 
   bool checkLayoutInvalidationIsAllowed() const;
 
   PaintController* paintController() { return m_paintController.get(); }
 
   LayoutSize m_size;
@@ skipping 21 matching lines @@
   bool m_hasPendingLayout;
   LayoutSubtreeRootList m_layoutSubtreeRootList;
   DepthOrderedLayoutObjectList m_orthogonalWritingModeRootList;
 
   bool m_layoutSchedulingEnabled;
   bool m_inSynchronousPostLayout;
   int m_layoutCount;
   unsigned m_nestedLayoutCount;
   Timer<FrameView> m_postLayoutTasksTimer;
   Timer<FrameView> m_updateWidgetsTimer;
-  std::unique_ptr<CancellableTaskFactory>
-      m_renderThrottlingObserverNotificationFactory;
 
   bool m_firstLayout;
   bool m_isTransparent;
   Color m_baseBackgroundColor;
   IntSize m_lastViewportSize;
   float m_lastZoomFactor;
 
   AtomicString m_mediaType;
   AtomicString m_mediaTypeWhenNotPrinting;
 
@@ skipping 60 matching lines @@
 
   // Mark if something has changed in the mapping from Frame to GraphicsLayer
   // and the Frame Timing regions should be recalculated.
   bool m_frameTimingRequestsDirty;
 
   // Exists only on root frame.
   // TODO(bokan): crbug.com/484188. We should specialize FrameView for the
   // main frame.
   Member<RootFrameViewport> m_viewportScrollableArea;
 
-  // This frame's bounds in the root frame's content coordinates, clipped
-  // recursively through every ancestor view.
-  IntRect m_viewportIntersection;
-  bool m_viewportIntersectionValid;
-
   // The following members control rendering pipeline throttling for this
   // frame. They are only updated in response to intersection observer
   // notifications, i.e., not in the middle of the lifecycle.
   bool m_hiddenForThrottling;
-  bool m_crossOriginForThrottling;
   bool m_subtreeThrottled;
 
   // Paint properties for SPv2 Only.
   // The hierarchy of transform subtree created by a FrameView.
   // [ preTranslation ]               The offset from Widget::frameRect.
   //     |                            Establishes viewport.
   //     +---[ scrollTranslation ]    Frame scrolling.
   // TODO(trchen): These will not be needed once settings->rootLayerScrolls() is
   // enabled.
   RefPtr<TransformPaintPropertyNode> m_preTranslation;
@@ skipping 10 matching lines @@
 
   // This is set on the local root frame view only.
   DocumentLifecycle::LifecycleState m_currentUpdateLifecyclePhasesTargetState;
 
   ScrollAnchor m_scrollAnchor;
 
   bool m_needsScrollbarsUpdate;
   bool m_suppressAdjustViewSize;
   bool m_allowsLayoutInvalidationAfterLayoutClean;
 
+  Member<IntersectionObserver> m_intersectionObserver;
+
   // For testing.
   struct ObjectPaintInvalidation {
     String name;
     PaintInvalidationReason reason;
   };
   std::unique_ptr<Vector<ObjectPaintInvalidation>>
       m_trackedObjectPaintInvalidations;
 
   // For Slimming Paint v2 only.
   std::unique_ptr<PaintController> m_paintController;
@@ skipping 31 matching lines @@
                   widget.isFrameView());
 DEFINE_TYPE_CASTS(FrameView,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->isFrameView(),
                   scrollableArea.isFrameView());
 
 }  // namespace blink
 
 #endif  // FrameView_h