If a GraphicsLayerChromium goes away during the middle of paint, its

Source/WebCore/platform/graphics/chromium/LayerRendererChromium.cpp

Index: Source/WebCore/platform/graphics/chromium/LayerRendererChromium.cpp
===================================================================
--- Source/WebCore/platform/graphics/chromium/LayerRendererChromium.cpp	(revision 94875)
+++ Source/WebCore/platform/graphics/chromium/LayerRendererChromium.cpp	(working copy)
@@ -563,6 +563,8 @@
         CCLayerImpl* renderSurfaceLayer = renderSurfaceLayerList[surfaceIndex].get();
         RenderSurfaceChromium* renderSurface = renderSurfaceLayer->renderSurface();
         ASSERT(renderSurface);
+        if (!renderSurface)
+            continue;
 
         renderSurface->setSkipsDraw(true);
 
@@ -964,6 +966,8 @@
         CCLayerImpl* renderSurfaceLayer = renderSurfaceLayerList[surfaceIndex].get();
         RenderSurfaceChromium* renderSurface = renderSurfaceLayer->renderSurface();
         ASSERT(renderSurface);
+        if (!renderSurface)
+            continue;
 
         if (!renderSurface->layerList().size() || !renderSurface->drawOpacity())
             continue;
@@ -972,6 +976,8 @@
         ASSERT(layerList.size());
         for (unsigned layerIndex = 0; layerIndex < layerList.size(); ++layerIndex) {
             CCLayerImpl* ccLayerImpl = layerList[layerIndex].get();
+            if (!ccLayerImpl)

[nduca, 2011/09/09 23:24:09]

(drive by) How do we prevent this crap from happening in the future? It seems to
me that rendersurfaces are crazy fragile as implemented.

+                continue;
             if (ccLayerImpl->renderSurface() && ccLayerImpl->renderSurface() != renderSurface)
                 continue;
 
@@ -1067,6 +1073,9 @@
 
 void LayerRendererChromium::drawLayer(CCLayerImpl* layer, RenderSurfaceChromium* targetSurface)
 {
+    if (!layer)
+        return;
+
     if (layer->renderSurface() && layer->renderSurface() != targetSurface) {
         layer->renderSurface()->draw(layer->getDrawRect());
         layer->renderSurface()->releaseContentsTexture();