Make RootScroller set the outer viewport scroll layer in the compositor

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/input/ScrollManager.h"
 
 #include "core/dom/DOMNodeIds.h"
 #include "core/events/GestureEvent.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/TopControls.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutPart.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/OverscrollController.h"
+#include "core/page/scrolling/RootScrollerController.h"
 #include "core/page/scrolling/ScrollState.h"
 #include "core/paint/PaintLayer.h"
 #include "platform/PlatformGestureEvent.h"
 #include "wtf/PtrUtil.h"
 #include <memory>
 
 
 namespace blink {
 
 ScrollManager::ScrollManager(LocalFrame* frame)
@@ skipping 314 matching lines @@
 bool ScrollManager::isEffectiveRootScroller(const Node& node) const
 {
     // The root scroller is the one Element on the page designated to perform
     // "viewport actions" like top controls movement and overscroll glow.
     if (!m_frame->document())
         return false;
 
     if (!node.isElementNode())
         return false;
 
-    return node.isSameNode(m_frame->document()->effectiveRootScroller());
+    return node.isSameNode(m_frame->document()->rootScrollerController()->effectiveRootScroller());
 }
 
 
 WebInputEventResult ScrollManager::handleGestureScrollEvent(const PlatformGestureEvent& gestureEvent)
 {
     Node* eventTarget = nullptr;
     Scrollbar* scrollbar = nullptr;
     if (gestureEvent.type() != PlatformEvent::GestureScrollBegin) {
         scrollbar = m_scrollbarHandlingScrollGesture.get();
         eventTarget = m_scrollGestureHandlingNode.get();
@@ skipping 140 matching lines @@
 DEFINE_TRACE(ScrollManager)
 {
     visitor->trace(m_frame);
     visitor->trace(m_scrollGestureHandlingNode);
     visitor->trace(m_previousGestureScrolledNode);
     visitor->trace(m_scrollbarHandlingScrollGesture);
     visitor->trace(m_resizeScrollableArea);
 }
 
 } // namespace blink