cc: Give non-drawing layers that are rasterized a lower priority.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index f43c977f6846f5e1cacb58731f69821164c62a34..130c6adcd3b586af2093aa2f5cf7a9029206f7b0 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -515,9 +515,13 @@ bool PictureLayerImpl::UpdateTiles() {
   // The reason for this is that we should be able to activate sooner and get a
   // more up to date recording, so we don't run out of recording on the active
   // tree.
-  bool can_require_tiles_for_activation =
-      !only_used_low_res_last_append_quads_ || RequiresHighResToDraw() ||
-      !layer_tree_impl()->SmoothnessTakesPriority();
+  // A layer must be a drawing layer for it to require tiles for activation.
+  bool can_require_tiles_for_activation = false;
+  if (contributes_to_drawn_render_surface()) {
+    can_require_tiles_for_activation =
+        !only_used_low_res_last_append_quads_ || RequiresHighResToDraw() ||
+        !layer_tree_impl()->SmoothnessTakesPriority();
+  }
 
   static const Occlusion kEmptyOcclusion;
   const Occlusion& occlusion_in_content_space =