Use float for scroll offset.

third_party/WebKit/Source/core/input/EventHandler.cpp

Index: third_party/WebKit/Source/core/input/EventHandler.cpp
diff --git a/third_party/WebKit/Source/core/input/EventHandler.cpp b/third_party/WebKit/Source/core/input/EventHandler.cpp
index d6a544c8f9d634b140d37c6ba31d32d387a0656a..c31464529b27022ca02f752885b7041c6351c5ed 100644
--- a/third_party/WebKit/Source/core/input/EventHandler.cpp
+++ b/third_party/WebKit/Source/core/input/EventHandler.cpp
@@ -1797,9 +1797,10 @@ WebInputEventResult EventHandler::sendContextMenuEventForKey(
         visualViewport.viewportToRootFrame(clippedRect.center());
   } else {
     locationInRootFrame = IntPoint(
-        rightAligned ? visualViewport.visibleRect().maxX() - kContextMenuMargin
-                     : visualViewport.location().x() + kContextMenuMargin,
-        visualViewport.location().y() + kContextMenuMargin);
+        rightAligned
+            ? visualViewport.visibleRect().maxX() - kContextMenuMargin
+            : visualViewport.scrollOffset().width() + kContextMenuMargin,
+        visualViewport.scrollOffset().height() + kContextMenuMargin);
   }
 
   m_frame->view()->setCursor(pointerCursor());