Tie scroll anchoring adjustments to frame lifecycle instead of layout.

third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp

Index: third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp
diff --git a/third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp b/third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp
index 2e6ccba0270b3e88420e1c89819ea7bf76233bb6..591a0507c30c0520e441f01f008be7fcf45ed609 100644
--- a/third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp
+++ b/third_party/WebKit/Source/core/frame/DOMVisualViewport.cpp
@@ -86,7 +86,7 @@ float DOMVisualViewport::pageX() {
   if (!view)
     return 0;
 
-  frame->document()->updateStyleAndLayoutIgnorePendingStylesheets();
+  frame->document()->updateScrollPosition();
   float viewportX = view->getScrollableArea()->scrollOffset().width();
   return adjustScrollForAbsoluteZoom(viewportX, frame->pageZoomFactor());
 }
@@ -100,7 +100,7 @@ float DOMVisualViewport::pageY() {
   if (!view)
     return 0;
 
-  frame->document()->updateStyleAndLayoutIgnorePendingStylesheets();
+  frame->document()->updateScrollPosition();
   float viewportY = view->getScrollableArea()->scrollOffset().height();
   return adjustScrollForAbsoluteZoom(viewportY, frame->pageZoomFactor());
 }