| Index: third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp
|
| diff --git a/third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp b/third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp
|
| index 0125aa0da4c16dcf65be4480bfc40b2cf8714df9..c8c9761ab92f6a1ad280d6af8fd2aba66baecee7 100644
|
| --- a/third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp
|
| +++ b/third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp
|
| @@ -10,6 +10,8 @@
|
| #include "core/frame/FrameView.h"
|
| #include "core/layout/LayoutBox.h"
|
| #include "core/layout/api/LayoutViewItem.h"
|
| +#include "core/layout/compositing/PaintLayerCompositor.h"
|
| +#include "core/paint/PaintLayer.h"
|
| #include "core/paint/PaintLayerScrollableArea.h"
|
| #include "platform/graphics/GraphicsLayer.h"
|
| #include "platform/scroll/ScrollableArea.h"
|
| @@ -100,8 +102,23 @@ void RootScrollerController::recomputeEffectiveRootScroller()
|
| if (m_effectiveRootScroller == newEffectiveRootScroller)
|
| return;
|
|
|
| + PaintLayer* oldRootScrollerLayer = rootScrollerPaintLayer();
|
| +
|
| m_effectiveRootScroller = newEffectiveRootScroller;
|
|
|
| + // This change affects both the old and new layers.
|
| + if (oldRootScrollerLayer)
|
| + oldRootScrollerLayer->setNeedsCompositingInputsUpdate();
|
| + if (rootScrollerPaintLayer())
|
| + rootScrollerPaintLayer()->setNeedsCompositingInputsUpdate();
|
| +
|
| + // The above may not be enough as we need to update existing ancestor
|
| + // GraphicsLayers. This will force us to rebuild the GraphicsLayer tree.
|
| + if (LayoutView* layoutView = m_document->layoutView()) {
|
| + layoutView->compositor()
|
| + ->setNeedsCompositingUpdate(CompositingUpdateRebuildTree);
|
| + }
|
| +
|
| m_document->topDocument().rootScrollerController()
|
| ->globalRootScrollerMayHaveChanged();
|
| }
|
| @@ -172,6 +189,27 @@ bool RootScrollerController::isViewportScrollCallback(
|
| return topDocumentController->isViewportScrollCallback(callback);
|
| }
|
|
|
| +PaintLayer* RootScrollerController::rootScrollerPaintLayer() const
|
| +{
|
| + if (!m_effectiveRootScroller
|
| + || !m_effectiveRootScroller->layoutObject()
|
| + || !m_effectiveRootScroller->layoutObject()->isBox())
|
| + return nullptr;
|
| +
|
| + LayoutBox* box = toLayoutBox(m_effectiveRootScroller->layoutObject());
|
| + PaintLayer* layer = box->layer();
|
| +
|
| + // If the root scroller is the <html> element we do a bit of a fake out because
|
| + // while <html> has a PaintLayer, scrolling for it is handled by the #document's
|
| + // PaintLayer (i.e. the PaintLayerCompositor's root layer). The reason the root
|
| + // scroller is the <html> layer and not #document is because the latter is a Node
|
| + // but not an Element.
|
| + if (m_effectiveRootScroller->isSameNode(m_document->documentElement()))
|
| + return layer->compositor()->rootLayer();
|
| +
|
| + return layer;
|
| +}
|
| +
|
| Element* RootScrollerController::defaultEffectiveRootScroller()
|
| {
|
| DCHECK(m_document);
|
|
|