Layout overflow from transforms should update frame scrollbars

Source/platform/scroll/ScrollView.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 13 matching lines @@
  */
 
 #include "config.h"
 #include "platform/scroll/ScrollView.h"
 
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "platform/graphics/GraphicsLayer.h"
 #include "platform/HostWindow.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "wtf/StdLibExtras.h"
-#include "wtf/TemporaryChange.h"
 
 using namespace std;
 
 namespace WebCore {
 
+ScrollView::InUpdateScrollbarsScope::InUpdateScrollbarsScope(ScrollView* view)

[ojan, 2014/06/11 03:04:53]

Nit: This constructor doesn't really do any work. I'd just put it in the header.

[trchen, 2014/06/11 05:04:13]

SGTM. I was hesitating.

+    : m_scope(view->m_inUpdateScrollbars, true)
+{
+}
+
 ScrollView::ScrollView()
     : m_horizontalScrollbarMode(ScrollbarAuto)
     , m_verticalScrollbarMode(ScrollbarAuto)
     , m_horizontalScrollbarLock(false)
     , m_verticalScrollbarLock(false)
     , m_scrollbarsAvoidingResizer(0)
     , m_scrollbarsSuppressed(false)
     , m_inUpdateScrollbars(false)
     , m_drawPanScrollIcon(false)
     , m_paintsEntireContents(false)
@@ skipping 401 matching lines @@
     if (!useOverlayScrollbars())
         contentsResized();
     scrollbarExistenceDidChange();
     return true;
 }
 
 void ScrollView::updateScrollbars(const IntSize& desiredOffset)
 {
     if (m_inUpdateScrollbars)
         return;
-    TemporaryChange<bool> inUpdateScrollbarsChange(m_inUpdateScrollbars, true);
+    InUpdateScrollbarsScope inUpdateScrollbarsScope(this);
 
     IntSize oldVisibleSize = visibleSize();
 
     bool scrollbarExistenceChanged = false;
     int maxUpdateScrollbarsPass = useOverlayScrollbars() || m_scrollbarsSuppressed ? 1 : 3;
     for (int updateScrollbarsPass = 0; updateScrollbarsPass < maxUpdateScrollbarsPass; updateScrollbarsPass++) {
         if (!adjustScrollbarExistence(updateScrollbarsPass ? Incremental : FirstPass))
             break;
         scrollbarExistenceChanged = true;
     }
@@ skipping 646 matching lines @@
         return;
 
     ScrollableArea::setScrollOrigin(origin);
 
     // Update if the scroll origin changes, since our position will be different if the content size did not change.
     if (updatePositionAtAll && updatePositionSynchronously)
         updateScrollbars(scrollOffset());
 }
 
 } // namespace WebCore