Add flag for drawing layers to screen with Ganesh

cc/layers/draw_properties.h

Index: cc/layers/draw_properties.h
diff --git a/cc/layers/draw_properties.h b/cc/layers/draw_properties.h
index ad598bc46f6dceeebd16cf49712dad7e7a9be22d..c9bd90c06abb9b6ab5e1c201e2728fa4ff4bf817 100644
--- a/cc/layers/draw_properties.h
+++ b/cc/layers/draw_properties.h
@@ -27,7 +27,8 @@ struct CC_EXPORT DrawProperties {
         contents_scale_x(1.f),
         contents_scale_y(1.f),
         num_descendants_that_draw_content(0),
-        descendants_can_clip_selves(false) {}
+        descendants_can_clip_selves(false),
+        can_draw_directly_to_backbuffer(false) {}
 
   // Transforms objects from content space to target surface space, where
   // this layer would be drawn.
@@ -89,6 +90,8 @@ struct CC_EXPORT DrawProperties {
   // If true, every descendant in the sub-tree can clip itself without the
   // need to use hardware sissoring or a new render target.
   bool descendants_can_clip_selves;
+
+  bool can_draw_directly_to_backbuffer;
 };
 
 }  // namespace cc