Style changes shouldn't cause RenderLayerCompositor to rebuild its tree

Source/core/rendering/compositing/RenderLayerCompositor.cpp

 /*
  * Copyright (C) 2009, 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 345 matching lines @@
 
     if (m_forceCompositingMode && !m_compositing)
         enableCompositingMode(true);
 
     if (!m_needsToRecomputeCompositingRequirements && !m_compositing)
         return;
 
     switch (updateType) {
     case CompositingUpdateAfterStyleChange:
         m_needsToRecomputeCompositingRequirements = true;
+        m_needsToUpdateLayerTreeGeometry = true;
         break;
     case CompositingUpdateAfterLayout:
         m_needsToRecomputeCompositingRequirements = true;
         // FIXME: Ideally we'd be smarter about tracking dirtiness and wouldn't need a ForceUpdate here.
         m_pendingUpdateType = GraphicsLayerUpdater::ForceUpdate;
         // FIXME: Ideally we'd be smarter about tracking dirtiness and wouldn't need a ForceUpdate here.
         m_pendingPropertyUpdateType = CompositingPropertyUpdater::ForceUpdate;
         break;
     case CompositingUpdateOnScroll:
         m_needsToRecomputeCompositingRequirements = true; // Overlap can change with scrolling, so need to check for hierarchy updates.
@@ skipping 434 matching lines @@
     }
     return update;
 }
 
 // These are temporary hacks to work around chicken-egg issues while we continue to refactor the compositing code.
 // See crbug.com/339892 for a list of tests that fail if this method is removed.
 void RenderLayerCompositor::applyUpdateLayerCompositingStateChickenEggHacks(RenderLayer* layer, CompositingStateTransitionType compositedLayerUpdate)
 {
     // See if we need content or clipping layers. Methods called here should assume
     // that the compositing state of descendant layers has not been updated yet.
-    if (layer->hasCompositedLayerMapping() && layer->compositedLayerMapping()->updateGraphicsLayerConfiguration(GraphicsLayerUpdater::ForceUpdate)) {
+    if (layer->hasCompositedLayerMapping() && layer->compositedLayerMapping()->updateGraphicsLayerConfiguration(GraphicsLayerUpdater::ForceUpdate))
         setCompositingLayersNeedRebuild();
-    } else if (compositedLayerUpdate == NoCompositingStateChange) {
-        if (layer->compositingState() == PaintsIntoOwnBacking || layer->compositingState() == HasOwnBackingButPaintsIntoAncestor)
-            setCompositingLayersNeedRebuild();
-    }
 
     if (compositedLayerUpdate != NoCompositingStateChange)
         allocateOrClearCompositedLayerMapping(layer, computeCompositedLayerUpdate(layer));
 }
 
 void RenderLayerCompositor::updateLayerCompositingState(RenderLayer* layer, UpdateLayerCompositingStateOptions options)
 {
     updateDirectCompositingReasons(layer);
     CompositingStateTransitionType compositedLayerUpdate = computeCompositedLayerUpdate(layer);
 
@@ skipping 1314 matching lines @@
     } else if (graphicsLayer == m_scrollLayer.get()) {
         name = "LocalFrame Scrolling Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore