[S.P.] Don't draw frames of animated images that are offscreen.

Source/core/layout/LayoutImage.h

Index: Source/core/layout/LayoutImage.h
diff --git a/Source/core/layout/LayoutImage.h b/Source/core/layout/LayoutImage.h
index 88b145ba4868dc680a0c0aa1451d9afb4b929152..34567dd7ffcbddea8a49ffa9559d00c154c5096a 100644
--- a/Source/core/layout/LayoutImage.h
+++ b/Source/core/layout/LayoutImage.h
@@ -83,6 +83,8 @@ protected:
 
     virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectLayoutImage || LayoutReplaced::isOfType(type); }
 
+    virtual PaintInvalidationReason invalidatePaintIfNeeded(const PaintInvalidationState&, const LayoutBoxModelObject&) override;
+
 private:
     virtual bool isImage() const override { return true; }
 
@@ -105,6 +107,9 @@ private:
     // Update the size of the image to be rendered. Object-fit may cause this to be different from the CSS box's content rect.
     void updateInnerContentRect();
 
+    // The given rect is in the local coordinate space of the LayoutImage.
+    bool rectIntersectsVisibleViewport(const LayoutRect&);
+
     // Text to display as long as the image isn't available.
     OwnPtr<LayoutImageResource> m_imageResource;
     bool m_didIncrementVisuallyNonEmptyPixelCount;