Re-land of issue 200623006: Set geometry dirty bits on composited layer mappings w/squashing

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 3538 matching lines @@
         if (RenderLayer* compositingParent = enclosingCompositingLayer(ExcludeSelf))
             compositingParent->compositedLayerMapping()->setNeedsGeometryUpdate();
     }
 
     m_compositedLayerMapping.clear();
 
     if (!layerBeingDestroyed)
         updateOrRemoveFilterEffectRenderer();
 }
 
+void RenderLayer::setGroupedMapping(CompositedLayerMapping* groupedMapping, bool layerBeingDestroyed)
+{
+    if (!layerBeingDestroyed && m_groupedMapping)

[ojan, 2014/03/19 18:54:00]

Nit, can this be one if statement?

if (!layerBeingDestroyed && (m_groupedMapping || groupedMapping))

[chrishtr, 2014/03/19 19:27:42]

It could, but then it would have to have two lines inside it to dirty the before
and after mapping.

+        m_groupedMapping->setNeedsGeometryUpdate();
+    m_groupedMapping = groupedMapping;
+    if (!layerBeingDestroyed && m_groupedMapping)
+        m_groupedMapping->setNeedsGeometryUpdate();
+}
+
 bool RenderLayer::hasCompositedMask() const
 {
     return m_compositedLayerMapping && m_compositedLayerMapping->hasMaskLayer();
 }
 
 bool RenderLayer::hasCompositedClippingMask() const
 {
     return m_compositedLayerMapping && m_compositedLayerMapping->hasChildClippingMaskLayer();
 }
 
@@ skipping 494 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif