Merge 124888

Source/WebCore/rendering/RenderFullScreen.cpp

 /*
  * Copyright (C) 2010 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 99 matching lines @@
     RenderFullScreen* fullscreenRenderer = new (document->renderArena()) RenderFullScreen(document);
     fullscreenRenderer->setStyle(createFullScreenStyle());
     if (parent && !parent->isChildAllowed(fullscreenRenderer, fullscreenRenderer->style())) {
         fullscreenRenderer->destroy();
         return 0;
     }
     if (object) {
         // |object->parent()| can be null if the object is not yet attached
         // to |parent|.
         if (RenderObject* parent = object->parent()) {
+            RenderBlock* containingBlock = object->containingBlock();
+            ASSERT(containingBlock);
+            // Since we are moving the |object| to a new parent |fullscreenRenderer|,
+            // the line box tree underneath our |containingBlock| is not longer valid.
+            containingBlock->deleteLineBoxTree();
+
             parent->addChild(fullscreenRenderer, object);
             object->remove();
+            
+            // Always just do a full layout to ensure that line boxes get deleted properly.
+            // Because objects moved from |parent| to |fullscreenRenderer|, we want to
+            // make new line boxes instead of leaving the old ones around.
             parent->setNeedsLayoutAndPrefWidthsRecalc();
+            containingBlock->setNeedsLayoutAndPrefWidthsRecalc();
         }
         fullscreenRenderer->addChild(object);
         fullscreenRenderer->setNeedsLayoutAndPrefWidthsRecalc();
     }
     document->setFullScreenRenderer(fullscreenRenderer);
     return fullscreenRenderer;
 }
 
 void RenderFullScreen::unwrapRenderer()
 {
@@ skipping 28 matching lines @@
         m_placeholder->setStyle(style);
         if (parent()) {
             parent()->addChild(m_placeholder, this);
             parent()->setNeedsLayoutAndPrefWidthsRecalc();
         }
     } else
         m_placeholder->setStyle(style);
 }
 
 #endif