<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!DOCTYPE bugzilla SYSTEM "https://bugs.webkit.org/page.cgi?id=bugzilla.dtd">

<bugzilla version="5.0.4.1"
          urlbase="https://bugs.webkit.org/"
          
          maintainer="admin@webkit.org"
>

    <bug>
          <bug_id>139651</bug_id>
          
          <creation_ts>2014-12-15 13:53:50 -0800</creation_ts>
          <short_desc>Lazily recompute the nonFastScrollableRegion</short_desc>
          <delta_ts>2015-05-01 15:37:32 -0700</delta_ts>
          <reporter_accessible>1</reporter_accessible>
          <cclist_accessible>1</cclist_accessible>
          <classification_id>1</classification_id>
          <classification>Unclassified</classification>
          <product>WebKit</product>
          <component>Layout and Rendering</component>
          <version>528+ (Nightly build)</version>
          <rep_platform>Unspecified</rep_platform>
          <op_sys>Unspecified</op_sys>
          <bug_status>RESOLVED</bug_status>
          <resolution>FIXED</resolution>
          
          
          <bug_file_loc></bug_file_loc>
          <status_whiteboard></status_whiteboard>
          <keywords></keywords>
          <priority>P2</priority>
          <bug_severity>Normal</bug_severity>
          <target_milestone>---</target_milestone>
          
          
          <everconfirmed>1</everconfirmed>
          <reporter name="Simon Fraser (smfr)">simon.fraser</reporter>
          <assigned_to name="Simon Fraser (smfr)">simon.fraser</assigned_to>
          <cc>simon.fraser</cc>
    
    <cc>thorton</cc>
    
    <cc>zalan</cc>
          

      

      

      

          <comment_sort_order>oldest_to_newest</comment_sort_order>  
          <long_desc isprivate="0" >
    <commentid>1055729</commentid>
    <comment_count>0</comment_count>
    <who name="Simon Fraser (smfr)">simon.fraser</who>
    <bug_when>2014-12-15 13:53:50 -0800</bug_when>
    <thetext>Profiling cssom/non-subpixel-scroll-top-left-values.html is very slow on Yosemite in debug shows 25% of time under:

Running Time	Self		Symbol Name
2310.0ms   28.0%	0.0	                           WebCore::Element::setInnerHTML(WTF::String const&amp;, int&amp;)
2281.0ms   27.7%	0.0	                            WebCore::replaceChildrenWithFragment(WebCore::ContainerNode&amp;, WTF::PassRefPtr&lt;WebCore::DocumentFragment&gt;, int&amp;)
2279.0ms   27.7%	0.0	                             WebCore::ContainerNode::removeChildren()
2277.0ms   27.6%	0.0	                              WebCore::ContainerNode::removeBetween(WebCore::Node*, WebCore::Node*, WebCore::Node&amp;)
2277.0ms   27.6%	0.0	                               WebCore::destroyRenderTreeIfNeeded(WebCore::Node&amp;)
2276.0ms   27.6%	0.0	                                WebCore::Style::detachRenderTree(WebCore::Element&amp;)
2276.0ms   27.6%	0.0	                                 WebCore::Style::detachRenderTree(WebCore::Element&amp;, WebCore::Style::DetachType)
2228.0ms   27.1%	0.0	                                  WebCore::RenderObject::destroyAndCleanupAnonymousWrappers()
2228.0ms   27.1%	0.0	                                   WebCore::RenderObject::destroy()
2220.0ms   27.0%	0.0	                                    WebCore::RenderBlockFlow::willBeDestroyed()
2220.0ms   27.0%	0.0	                                     WebCore::RenderBoxModelObject::willBeDestroyed()
2220.0ms   27.0%	0.0	                                      WebCore::RenderElement::willBeDestroyed()
2220.0ms   27.0%	0.0	                                       WebCore::RenderObject::willBeDestroyed()
2195.0ms   26.6%	0.0	                                        WebCore::RenderLayerModelObject::destroyLayer()
2195.0ms   26.6%	0.0	                                         WebCore::RenderLayer::~RenderLayer()
2193.0ms   26.6%	0.0	                                          WebCore::RenderLayer::~RenderLayer()
2193.0ms   26.6%	0.0	                                           WebCore::RenderLayer::~RenderLayer()
2120.0ms   25.7%	0.0	                                            WebCore::FrameView::removeScrollableArea(WebCore::ScrollableArea*)
2118.0ms   25.7%	0.0	                                             WebCore::FrameView::scrollableAreaSetChanged()
2118.0ms   25.7%	0.0	                                              WebCore::AsyncScrollingCoordinator::frameViewNonFastScrollableRegionChanged(WebCore::FrameView*)
2113.0ms   25.7%	4.0	                                               WebCore::ScrollingCoordinator::computeNonFastScrollableRegion(WebCore::Frame const*, WebCore::IntPoint const&amp;) const
1543.0ms   18.7%	5.0	                                                WebCore::Region::unite(WebCore::Region const&amp;)
1356.0ms   16.4%	2.0	                                                 WebCore::Region::Shape::unionShapes(WebCore::Region::Shape const&amp;, WebCore::Region::Shape const&amp;)
1351.0ms   16.4%	15.0	                                                  WebCore::Region::Shape WebCore::Region::Shape::shapeOperation&lt;WebCore::Region::Shape::UnionOperation&gt;(WebCore::Region::Shape const&amp;, WebCore::Region::Shape const&amp;)
658.0ms    8.0%	4.0	                                                   WebCore::Region::Shape::appendSpan(int, int const*, int const*)

We should compute this region lazily.</thetext>
  </long_desc><long_desc isprivate="0" >
    <commentid>1090920</commentid>
    <comment_count>1</comment_count>
    <who name="Simon Fraser (smfr)">simon.fraser</who>
    <bug_when>2015-05-01 15:37:32 -0700</bug_when>
    <thetext>Fixed in r182346.</thetext>
  </long_desc>
      
      

    </bug>

</bugzilla>