cc: Support mask layers in impl-side painting

cc/layer_tree_host_common.cc

Index: cc/layer_tree_host_common.cc
diff --git a/cc/layer_tree_host_common.cc b/cc/layer_tree_host_common.cc
index 3fccbf12389f8ff0ebec4c0b0b70cc0d932ceb10..b4257e8efa1587836c59e6e361ad1473f72d85c7 100644
--- a/cc/layer_tree_host_common.cc
+++ b/cc/layer_tree_host_common.cc
@@ -233,6 +233,16 @@ static inline bool subtreeShouldBeSkipped(Layer* layer)
 static inline void markLayerAsUpdated(LayerImpl* layer)
 {
     layer->didUpdateTransforms();
+
+    // Mask layers don't get this call, so explicitly update them so they can
+    // kick off tile rasterization.
+    if (layer->maskLayer())
+        layer->maskLayer()->didUpdateTransforms();
+    if (layer->replicaLayer()) {
+        layer->replicaLayer()->didUpdateTransforms();
+        if (layer->replicaLayer()->maskLayer())
+            layer->replicaLayer()->maskLayer()->didUpdateTransforms();
+    }
 }
 
 static inline void markLayerAsUpdated(Layer* layer)