Serialize PictureLayer properties.

cc/layers/layer_proto_converter.cc

Index: cc/layers/layer_proto_converter.cc
diff --git a/cc/layers/layer_proto_converter.cc b/cc/layers/layer_proto_converter.cc
index 65e1b14ff0c1d4043bbeb7da17e7fa725393e0de..6564e0bf42886c93933c11c8767546dc831715d7 100644
--- a/cc/layers/layer_proto_converter.cc
+++ b/cc/layers/layer_proto_converter.cc
@@ -5,8 +5,10 @@
 #include "cc/layers/layer_proto_converter.h"
 
 #include "base/stl_util.h"
+#include "cc/layers/empty_content_layer_client.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/layer_settings.h"
+#include "cc/layers/picture_layer.h"
 #include "cc/proto/layer.pb.h"
 #include "cc/trees/layer_tree_host_common.h"
 #include "cc/trees/layer_tree_settings.h"
@@ -103,8 +105,15 @@ scoped_refptr<Layer> LayerProtoConverter::FindOrAllocateAndConstruct(
     return iter->second;
   DCHECK(proto.has_type());
   switch (proto.type()) {
-    case proto::Base:
+    // Fall through and build a base layer.  This won't have any special layer
+    // properties but still maintains the layer hierarchy if we run into a
+    // layer type we don't support.
+    case proto::UNKNOWN:
+    case proto::LAYER:
       return Layer::Create(LayerSettings()).get();
+    case proto::PICTURE_LAYER:
+      return PictureLayer::Create(LayerSettings(),
+                                  EmptyContentLayerClient::GetInstance());
   }
   // TODO(nyquist): Add the rest of the necessary LayerTypes. This function
   // should not return null.