Index: third_party/WebKit/Source/core/page/scrolling/RootScrollerUtil.cpp |
diff --git a/third_party/WebKit/Source/core/page/scrolling/RootScrollerUtil.cpp b/third_party/WebKit/Source/core/page/scrolling/RootScrollerUtil.cpp |
index 4940df7bb9d775466499d6dbfeb1b5966f1e3027..6f7adfcbfd48620ceaf28af3882886c2468271ab 100644 |
--- a/third_party/WebKit/Source/core/page/scrolling/RootScrollerUtil.cpp |
+++ b/third_party/WebKit/Source/core/page/scrolling/RootScrollerUtil.cpp |
@@ -7,7 +7,10 @@ |
#include "core/dom/Document.h" |
#include "core/dom/Element.h" |
#include "core/frame/FrameView.h" |
+#include "core/layout/LayoutBox.h" |
#include "core/layout/LayoutBoxModelObject.h" |
+#include "core/layout/compositing/PaintLayerCompositor.h" |
+#include "core/paint/PaintLayer.h" |
#include "core/paint/PaintLayerScrollableArea.h" |
namespace blink { |
@@ -33,6 +36,27 @@ ScrollableArea* scrollableAreaFor(const Element& element) { |
toLayoutBoxModelObject(element.layoutObject())->getScrollableArea()); |
} |
+PaintLayer* paintLayerFor(const Element* element) { |
+ if (!element || !element->layoutObject() || !element->layoutObject()->isBox()) |
chrishtr
2016/11/18 00:37:09
Is it possible for it to be a non-box, or is this
bokan
2016/11/18 22:30:35
If an element is the root scroller it must be a bo
|
+ return nullptr; |
+ |
+ LayoutBox* box = toLayoutBox(element->layoutObject()); |
+ PaintLayer* layer = box->layer(); |
chrishtr
2016/11/18 00:37:09
DCHECK(layer);
bokan
2016/11/18 22:30:35
It's now just used for return.
|
+ |
+ // 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 (element->isSameNode(element->document().documentElement())) { |
+ if (!layer || !layer->compositor()) |
+ return nullptr; |
+ return layer->compositor()->rootLayer(); |
chrishtr
2016/11/18 00:37:09
I prefer:
return box->view()->layer()
bokan
2016/11/18 22:30:35
Done.
|
+ } |
+ |
+ return layer; |
+} |
+ |
} // namespace RootScrollerUtil |
} // namespace blink |