Intersection Observer support for OOPIF

third_party/WebKit/public/web/WebFrameWidget.h

Index: third_party/WebKit/public/web/WebFrameWidget.h
diff --git a/third_party/WebKit/public/web/WebFrameWidget.h b/third_party/WebKit/public/web/WebFrameWidget.h
index 4dd05097484d2ef191f66aabf2e5de29a0cea8c4..0a12dce4b6d51a4bb6145262b0e117002d97df23 100644
--- a/third_party/WebKit/public/web/WebFrameWidget.h
+++ b/third_party/WebKit/public/web/WebFrameWidget.h
@@ -112,9 +112,14 @@ class WebFrameWidget : public WebWidget {
                                  const WebPoint& screenPoint,
                                  WebDragOperation) = 0;
 
-  // Notfies the WebFrameWidget that the system drag and drop operation has
+  // Notifies the WebFrameWidget that the system drag and drop operation has
   // ended.
   virtual void dragSourceSystemDragEnded() = 0;
+
+  // Constrains the viewport intersection for use by IntersectionObserver.
+  // This is needed for out-of-process iframes to know if they are clipped
+  // by ancestor frames in another process.
+  virtual void setRemoteViewportIntersection(const WebRect&) {}
 };
 
 }  // namespace blink