Move middle-click autoscroll to synthetic fling.

third_party/WebKit/Source/core/layout/LayoutBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 619 matching lines @@
 }
 
 // Returns true iff we are attempting an autoscroll inside an iframe with
 // scrolling="no".
 static bool IsDisallowedAutoscroll(HTMLFrameOwnerElement* owner_element,
                                    LocalFrameView* frame_view) {
   if (owner_element && IsHTMLFrameElementBase(*owner_element)) {
     HTMLFrameElementBase* frame_element_base =
         ToHTMLFrameElementBase(owner_element);
     if (Page* page = frame_view->GetFrame().GetPage()) {
-      return page->GetAutoscrollController().AutoscrollInProgress() &&
+      return page->GetAutoscrollController().SelectionAutoscrollInProgress() &&
              frame_element_base->ScrollingMode() == kScrollbarAlwaysOff;
     }
   }
   return false;
 }
 
 void LayoutBox::ScrollRectToVisible(const LayoutRect& rect,
                                     const ScrollAlignment& align_x,
                                     const ScrollAlignment& align_y,
                                     ScrollType scroll_type,
@@ skipping 79 matching lines @@
     }
   }
 
   // If we are fixed-position and stick to the viewport, it is useless to
   // scroll the parent.
   if (Style()->GetPosition() == EPosition::kFixed &&
       ContainerForFixedPosition() == View()) {
     return;
   }
 
-  if (GetFrame()->GetPage()->GetAutoscrollController().AutoscrollInProgress())
+  if (GetFrame()
+          ->GetPage()
+          ->GetAutoscrollController()
+          .SelectionAutoscrollInProgress())
     parent_box = EnclosingScrollableBox();
 
   if (parent_box) {
     parent_box->ScrollRectToVisibleRecursive(
         new_rect, align_x, align_y, scroll_type,
         make_visible_in_visual_viewport, scroll_behavior);
   }
 }
 
 void LayoutBox::AbsoluteRects(Vector<IntRect>& rects,
@@ skipping 5209 matching lines @@
 void LayoutBox::MutableForPainting::
     SavePreviousContentBoxSizeAndLayoutOverflowRect() {
   auto& rare_data = GetLayoutBox().EnsureRareData();
   rare_data.has_previous_content_box_size_and_layout_overflow_rect_ = true;
   rare_data.previous_content_box_size_ = GetLayoutBox().ContentBoxRect().Size();
   rare_data.previous_layout_overflow_rect_ =
       GetLayoutBox().LayoutOverflowRect();
 }
 
 }  // namespace blink