Intersection Observer support for OOPIF

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

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index 47517031fb0df30b62b0d5d9b144923ef2b6f379..1947fd18d51c9905d2514f8d72558635b6cbb91c 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -31,6 +31,7 @@
 #include "core/frame/FrameViewAutoSizeInfo.h"
 #include "core/frame/LayoutSubtreeRootList.h"
 #include "core/frame/RootFrameViewport.h"
+#include "core/layout/MapCoordinatesFlags.h"
 #include "core/layout/ScrollAnchor.h"
 #include "core/paint/FirstMeaningfulPaintDetector.h"
 #include "core/paint/ObjectPaintProperties.h"
@@ -803,6 +804,24 @@ class CORE_EXPORT FrameView final
 
   bool hasVisibleSlowRepaintViewportConstrainedObjects() const;
 
+  // Called on a view for a LocalFrame with a RemoteFrame parent. This makes
+  // viewport intersection available that accounts for remote ancestor frames
+  // and their respective scroll positions, clips, etc.
+  void setViewportIntersectionFromParent(const IntRect&);
+  IntRect remoteViewportIntersection();
+
+  // This method uses localToAncestorQuad to map a rect into an ancestor's
+  // coordinate space, while guaranteeing that the top-level scroll offset
+  // is accounted for. This is needed because LayoutView::mapLocalToAncestor()
+  // implicitly includes the ancestor frame's scroll offset when there is
+  // a remote frame in the ancestor chain, but does not include it when
+  // there are only local frames in the frame tree.
+  void mapQuadToAncestorFrameIncludingScrollOffset(

[dcheng, 2017/01/05 07:10:19]

Can we inline this directly, since it's only used from one place?

[szager1, 2017/01/05 20:25:22]

This is a generally useful method, I expect it to be used elsewhere in the
future.

+      LayoutRect&,
+      const LayoutObject* descendant,
+      const LayoutView* ancestor,
+      MapCoordinatesFlags mode);
+
  protected:
   // Scroll the content via the compositor.
   bool scrollContentsFastPath(const IntSize& scrollDelta);
@@ -1156,6 +1175,8 @@ class CORE_EXPORT FrameView final
 
   Member<ElementVisibilityObserver> m_visibilityObserver;
 
+  IntRect m_remoteViewportIntersection;
+
   // For testing.
   struct ObjectPaintInvalidation {
     String name;