cc: Move background filters to the effect tree

cc/proto/layer.proto

Index: cc/proto/layer.proto
diff --git a/cc/proto/layer.proto b/cc/proto/layer.proto
index 209a565efc9f3891225ed0fb0d5812ed1f2e36f8..c8ae18b85d081cacd125b25de0799e12cfde2fd9 100644
--- a/cc/proto/layer.proto
+++ b/cc/proto/layer.proto
@@ -67,7 +67,7 @@ message LayerProperties {
   optional SolidColorScrollbarLayerProperties solid_scrollbar = 7;
 }
 
-// NEXT ID: 54
+// NEXT ID: 55
 message BaseLayerProperties {
   optional Point3F transform_origin = 1;
   optional uint32 background_color = 2;
@@ -82,6 +82,7 @@ message BaseLayerProperties {
   optional bool draws_content = 9;
   optional bool hide_layer_and_subtree = 10;
   optional bool subtree_property_changed = 47;
+  optional bool layer_property_changed = 54;
   // TODO(nyquist): Add support for FilterOperation. See crbug.com/541321.
   // repeated FilterOperation filters = 12;
   // repeated FilterOperation background_filters = 13;