cc: Change TileManager iterators to be queues.

cc/layers/picture_layer_impl.h

Index: cc/layers/picture_layer_impl.h
diff --git a/cc/layers/picture_layer_impl.h b/cc/layers/picture_layer_impl.h
index 3b07c5dfd367897ce1e7b7524846c66c1908072a..03dff229db70e6b92d8e0cac8968b7a9946d1607 100644
--- a/cc/layers/picture_layer_impl.h
+++ b/cc/layers/picture_layer_impl.h
@@ -23,6 +23,15 @@ struct AppendQuadsData;
 class MicroBenchmarkImpl;
 class Tile;
 
+class PictureLayerImpl;
+struct CC_EXPORT PairedPictureLayer {
+  PairedPictureLayer();
+  ~PairedPictureLayer();
+
+  PictureLayerImpl* active_layer;
+  PictureLayerImpl* pending_layer;

[reveman, 2014/07/18 21:08:04]

nit: don't think _layer suffix is necessary.

[vmpstr, 2014/07/18 23:18:12]

Done.

+};

[reveman, 2014/07/18 21:08:04]

How about PictureLayerImpl::Pair? or simply std::pair?

[vmpstr, 2014/07/18 23:18:12]

Done. I prefer PictureLayerImpl::Pair so we have explicit names for which one is
active and which one is pending.

+
 class CC_EXPORT PictureLayerImpl
     : public LayerImpl,
       NON_EXPORTED_BASE(public PictureLayerTilingClient) {