cc: Remove some unnecessary const scoped_refptr&.

cc/layers/layer_proto_converter.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/layer_proto_converter.h"
 
 #include "base/stl_util.h"
 #include "cc/layers/empty_content_layer_client.h"
 #include "cc/layers/heads_up_display_layer.h"
 #include "cc/layers/layer.h"
@@ skipping 14 matching lines @@
     proto::LayerNode* root_node) {
   root_layer->ToLayerNodeProto(root_node);
 }
 
 // static
 scoped_refptr<Layer> LayerProtoConverter::DeserializeLayerHierarchy(
     scoped_refptr<Layer> existing_root,
     const proto::LayerNode& root_node) {
   LayerIdMap layer_id_map;
   if (existing_root)
-    RecursivelyFindAllLayers(existing_root, &layer_id_map);
+    RecursivelyFindAllLayers(existing_root.get(), &layer_id_map);
 
   scoped_refptr<Layer> new_root = existing_root;
   if (!existing_root ||
       (root_node.has_id() && root_node.id() != existing_root->id())) {
     // The root node has changed or there was no root node,
     // so find or create the new root.
     new_root = FindOrAllocateAndConstruct(root_node, layer_id_map);
   }
   new_root->FromLayerNodeProto(root_node, layer_id_map);
   return new_root;
@@ skipping 36 matching lines @@
   for (const auto& child : layer->children()) {
     RecursivelySerializeLayerProperties(child.get(), layer_update);
   }
   if (layer->mask_layer())
     RecursivelySerializeLayerProperties(layer->mask_layer(), layer_update);
   if (layer->replica_layer())
     RecursivelySerializeLayerProperties(layer->replica_layer(), layer_update);
 }
 
 // static
-void LayerProtoConverter::RecursivelyFindAllLayers(
-    const scoped_refptr<Layer>& layer,
-    LayerIdMap* layer_id_map) {
+void LayerProtoConverter::RecursivelyFindAllLayers(Layer* root_layer,
+                                                   LayerIdMap* layer_id_map) {
   LayerTreeHostCommon::CallFunctionForSubtree(
-      layer.get(),
+      root_layer,
       [layer_id_map](Layer* layer) { (*layer_id_map)[layer->id()] = layer; });

[danakj, 2016/03/16 00:08:15]

https://code.google.com/p/chromium/codesearch#chromium/src/cc/layers/layer_pr...

LayerIdMap is a map of refptrs. Does it need to hold ownership?

 }
 
 // static
 scoped_refptr<Layer> LayerProtoConverter::FindOrAllocateAndConstruct(
     const proto::LayerNode& proto,
     const Layer::LayerIdMap& layer_id_map) {
   DCHECK(proto.has_id());
   Layer::LayerIdMap::const_iterator iter = layer_id_map.find(proto.id());
   if (iter != layer_id_map.end())
     return iter->second;
@@ skipping 10 matching lines @@
     case proto::LayerNode::HEADS_UP_DISPLAY_LAYER:
       return HeadsUpDisplayLayer::Create();
   }
   // TODO(nyquist): Add the rest of the necessary LayerTypes. This function
   // should not return null.
   NOTREACHED();
   return nullptr;
 }
 
 }  // namespace cc