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

Source/core/platform/ScrollView.h

 /*
  * Copyright (C) 2004, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Holger Hans Peter Freyther
  *
  * 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
@@ skipping 124 matching lines @@
     // visibleContentRect().size() is computed from unscaledVisibleContentSize() divided by the value of visibleContentScaleFactor.
     // For the main frame, visibleContentScaleFactor is equal to the page's pageScaleFactor; it's 1 otherwise.
     IntSize unscaledVisibleContentSize(VisibleContentRectIncludesScrollbars = ExcludeScrollbars) const;
     virtual float visibleContentScaleFactor() const { return 1; }
 
     // Functions for getting/setting the size webkit should use to layout the contents. By default this is the same as the visible
     // content size. Explicitly setting a layout size value will cause webkit to layout the contents using this size instead.
     IntSize layoutSize() const;
     int layoutWidth() const { return layoutSize().width(); }
     int layoutHeight() const { return layoutSize().height(); }
+    // The spec DOM Level 2 Events states that the resize event occurs when document view size (a.k.a layout size) is changed. Refer to http://www.w3.org/TR/DOM-Level-2-Events/events.html
+    // However, we don't want scrollbar to emit a resize event because other browsers don't have this behavior, and actual site is badly affected. Refer to webkit.org/b/80242

[kenneth.r.christiansen, 2013/05/06 19:50:51]

I don't think this explains it very well. You want to say that showing/hiding
scrollbars shouldn't be considered a layout size change?

+    // So we use layoutSizeIncludingScrollbars() to emit a resize event due to above practical reason.
+    IntSize layoutSizeIncludingScrollbars() const;
     IntSize fixedLayoutSize() const;
     void setFixedLayoutSize(const IntSize&);
     bool useFixedLayout() const;
     void setUseFixedLayout(bool enable);
     
     // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
     // values).
     virtual IntSize contentsSize() const OVERRIDE; // Always at least as big as the visibleWidth()/visibleHeight().
     int contentsWidth() const { return contentsSize().width(); }
     int contentsHeight() const { return contentsSize().height(); }
@@ skipping 228 matching lines @@
     ASSERT(!widget || widget->isScrollView());
     return static_cast<const ScrollView*>(widget);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toScrollView(const ScrollView*);
 
 } // namespace WebCore
 
 #endif // ScrollView_h