Revert of Split RootScrollerController into top-document and child-document classes

third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp

Index: third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
diff --git a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
deleted file mode 100644
index 8cd2054593b5fbf1a876a1680462ad8e5f577c57..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
+++ /dev/null
@@ -1,111 +0,0 @@
-// 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/page/scrolling/TopDocumentRootScrollerController.h"
-
-#include "core/dom/Document.h"
-#include "core/dom/Element.h"
-#include "core/frame/FrameHost.h"
-#include "core/frame/FrameView.h"
-#include "core/page/ChromeClient.h"
-#include "core/page/scrolling/OverscrollController.h"
-#include "core/page/scrolling/ViewportScrollCallback.h"
-#include "platform/scroll/ScrollableArea.h"
-
-namespace blink {
-
-// static
-TopDocumentRootScrollerController* TopDocumentRootScrollerController::create(
-    Document& document)
-{
-    return new TopDocumentRootScrollerController(document);
-}
-
-TopDocumentRootScrollerController::TopDocumentRootScrollerController(
-    Document& document)
-    : RootScrollerController(document)
-{
-}
-
-DEFINE_TRACE(TopDocumentRootScrollerController)
-{
-    visitor->trace(m_viewportApplyScroll);
-    visitor->trace(m_currentViewportApplyScrollHost);
-    RootScrollerController::trace(visitor);
-}
-
-void TopDocumentRootScrollerController::updateEffectiveRootScroller()
-{
-    RootScrollerController::updateEffectiveRootScroller();
-    setViewportApplyScrollOnRootScroller();
-}
-
-void TopDocumentRootScrollerController::setViewportApplyScrollOnRootScroller()
-{
-    if (!m_viewportApplyScroll || !effectiveRootScroller())
-        return;
-
-    ScrollableArea* targetScroller =
-        scrollableAreaFor(*effectiveRootScroller());
-
-    if (!targetScroller)
-        return;
-
-    if (m_currentViewportApplyScrollHost)
-        m_currentViewportApplyScrollHost->removeApplyScroll();
-
-    // Use disable-native-scroll since the ViewportScrollCallback needs to
-    // apply scroll actions both before (TopControls) and after (overscroll)
-    // scrolling the element so it will apply scroll to the element itself.
-    effectiveRootScroller()->setApplyScroll(
-        m_viewportApplyScroll, "disable-native-scroll");
-
-    m_currentViewportApplyScrollHost = effectiveRootScroller();
-
-    // Ideally, scroll customization would pass the current element to scroll to
-    // the apply scroll callback but this doesn't happen today so we set it
-    // through a back door here. This is also needed by the
-    // ViewportScrollCallback to swap the target into the layout viewport
-    // in RootFrameViewport.
-    m_viewportApplyScroll->setScroller(targetScroller);
-}
-
-void TopDocumentRootScrollerController::didUpdateCompositing()
-{
-    FrameHost* frameHost = m_document->frameHost();
-
-    // Let the compositor-side counterpart know about this change.
-    if (frameHost)
-        frameHost->chromeClient().registerViewportLayers();
-}
-
-void TopDocumentRootScrollerController::didAttachDocument()
-{
-    FrameHost* frameHost = m_document->frameHost();
-    FrameView* frameView = m_document->view();
-
-    if (!frameHost || !frameView)
-        return;
-
-    RootFrameViewport* rootFrameViewport = frameView->getRootFrameViewport();
-    DCHECK(rootFrameViewport);
-
-    m_viewportApplyScroll = ViewportScrollCallback::create(
-        &frameHost->topControls(),
-        &frameHost->overscrollController(),
-        *rootFrameViewport);
-
-    updateEffectiveRootScroller();
-}
-
-bool TopDocumentRootScrollerController::isViewportScrollCallback(
-    const ScrollStateCallback* callback) const
-{
-    if (!callback)
-        return false;
-
-    return callback == m_viewportApplyScroll.get();
-}
-
-} // namespace blink