Implement a method to access the non-composited content root layer picture pile.

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index 55f6452ded8bc55344b72f71dc08478de00335a7..be3498294da112e531ed055a9e1787ff27afebf0 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -1724,4 +1724,32 @@ void LayerTreeHostImpl::animateScrollbarsRecursive(LayerImpl* layer, base::TimeT
         animateScrollbarsRecursive(layer->children()[i], time);
 }
 
+// static
+LayerImpl* LayerTreeHostImpl::getNonCompositedContentRootLayerRecursive(LayerImpl* layer)
+{
+    if (!layer)
+        return NULL;
+
+    if (layer->drawsContent())
+        return layer;
+
+    for (LayerImpl::LayerList::const_iterator it = layer->children().begin();
+            it != layer->children().end(); ++it) {
+        LayerImpl* nccr = getNonCompositedContentRootLayerRecursive(*it);
+        if (nccr)
+            return nccr;
+    }
+
+    return NULL;
+}
+
+scoped_refptr<PicturePileImpl> LayerTreeHostImpl::capturePicturePile()
+{
+    // Non-composited content root is the first drawable picture layer we find

[danakj, 2013/01/04 18:10:01]

nit: This comment seems misplaced or out of date. I think it could just go away.

[Leandro Graciá Gil, 2013/01/04 20:40:15]

Done.

+    // in a depth-first exploration from the root.
+    LayerTreeImpl* tree = pendingTree() ? pendingTree() : activeTree();
+    const LayerImpl* layer = getNonCompositedContentRootLayerRecursive(tree->RootLayer());
+    return layer ? layer->GetPicturePileClone() : scoped_refptr<PicturePileImpl>();
+}
+
 }  // namespace cc