Clarify the size of a document view (a.k.a layout size) that causes FrameView to emit the resize ev…

Source/core/platform/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 196 matching lines @@
 
 IntRect ScrollView::visibleContentRect(VisibleContentRectIncludesScrollbars scollbarInclusion) const
 {
     FloatSize visibleContentSize = unscaledVisibleContentSize(scollbarInclusion);
     visibleContentSize.scale(1 / visibleContentScaleFactor());
     return IntRect(IntPoint(m_scrollOffset), expandedIntSize(visibleContentSize));
 }
 
 IntSize ScrollView::layoutSize(VisibleContentRectIncludesScrollbars scrollbarInclusion) const
 {
-    return m_fixedLayoutSize.isEmpty() || !m_useFixedLayout ? unscaledVisibleContentSize(scrollbarInclusion) : m_fixedLayoutSize;
+    if (m_useFixedLayout) {
+        ASSERT(!m_fixedLayoutSize.isEmpty());

[aelias_OOO_until_Jul13, 2013/05/29 18:47:28]

This subtly changes the behavior in a way that might cause a regression (size
initialization is quite timing-sensitive) and I don't think it's needed to solve
the bug  so I suggest not touching this?

+        return m_fixedLayoutSize;
+    }
+    return unscaledVisibleContentSize(scrollbarInclusion);
 }
 
 IntSize ScrollView::fixedLayoutSize() const
 {
     return m_fixedLayoutSize;
 }
 
 void ScrollView::setFixedLayoutSize(const IntSize& newSize)
 {
     if (fixedLayoutSize() == newSize)
@@ skipping 1027 matching lines @@
 {
 }
 
 bool ScrollView::platformIsOffscreen() const
 {
     return false;
 }
 
 
 }