Make ViewportScrollCallback an interface and add child and root classes

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

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 3822b25a1edc66b69aaa002e0c44ec1a3e61c19e..f3b786b8e61d2f630bba6231510f68562abffac6 100644
--- a/third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp
+++ b/third_party/WebKit/Source/core/page/scrolling/RootScrollerController.cpp
@@ -12,7 +12,7 @@
 #include "core/layout/LayoutBox.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/OverscrollController.h"
-#include "core/page/scrolling/ViewportScrollCallback.h"
+#include "core/page/scrolling/RootViewportScrollCallback.h"

[tdresser, 2016/07/06 18:28:18]

Is this used?

[bokan, 2016/07/06 21:12:04]

Nope, this is a leftover from coding, it should really be
ViewportScrollCallback.h so I put it back in.

 #include "core/paint/PaintLayerScrollableArea.h"
 #include "platform/scroll/ScrollableArea.h"
 
@@ -73,12 +73,6 @@ bool isValidRootScroller(const Element& element)
 
 } // namespace
 
-ViewportScrollCallback* RootScrollerController::createViewportApplyScroll(
-    TopControls* topControls, OverscrollController* overscrollController)
-{
-    return new ViewportScrollCallback(topControls, overscrollController);
-}
-
 RootScrollerController::RootScrollerController(Document& document, ViewportScrollCallback* applyScrollCallback)
     : m_document(&document)
     , m_viewportApplyScroll(applyScrollCallback)