Fix GCC build for target 'all'

gpu/tools/compositor_model_bench/render_tree.cc

 // Copyright (c) 2012 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 "gpu/tools/compositor_model_bench/render_tree.h"
 
 #include <memory>
 #include <sstream>
 #include <vector>
 
@@ skipping 344 matching lines @@
   node.GetList("children", &children);
   for (unsigned int i = 0; i < children->GetSize(); ++i) {
     const base::DictionaryValue* childNode;
     if (!children->GetDictionary(i, &childNode))
       continue;
     std::unique_ptr<RenderNode> child = InterpretNode(*childNode);
     if (child)
       n->add_child(child.release());
   }
 
-  return n;
+  return std::move(n);
 }
 
 std::unique_ptr<RenderNode> InterpretCanvasLayer(
     const base::DictionaryValue& node) {
   auto n = base::MakeUnique<CCNode>();
   if (!InterpretCommonContents(node, n.get()))
     return nullptr;
 
   if (!VerifyDictionaryEntry(node, "type", Value::Type::STRING))
     return nullptr;
 
   std::string type;
   node.GetString("type", &type);
   assert(type == "CanvasLayer");
 
   if (!InterpretCCData(node, n.get()))
     return nullptr;
 
-  return n;
+  return std::move(n);
 }
 
 std::unique_ptr<RenderNode> InterpretVideoLayer(
     const base::DictionaryValue& node) {
   auto n = base::MakeUnique<CCNode>();
   if (!InterpretCommonContents(node, n.get()))
     return nullptr;
 
   if (!VerifyDictionaryEntry(node, "type", Value::Type::STRING))
     return nullptr;
 
   std::string type;
   node.GetString("type", &type);
   assert(type == "VideoLayer");
 
   if (!InterpretCCData(node, n.get()))
     return nullptr;
 
-  return n;
+  return std::move(n);
 }
 
 std::unique_ptr<RenderNode> InterpretImageLayer(
     const base::DictionaryValue& node) {
   auto n = base::MakeUnique<CCNode>();
   if (!InterpretCommonContents(node, n.get()))
     return nullptr;
 
   if (!VerifyDictionaryEntry(node, "type", Value::Type::STRING))
     return nullptr;
 
   std::string type;
   node.GetString("type", &type);
   assert(type == "ImageLayer");
 
   if (!InterpretCCData(node, n.get()))
     return nullptr;
 
-  return n;
+  return std::move(n);
 }
 
 std::unique_ptr<RenderNode> InterpretNode(const base::DictionaryValue& node) {
   if (!VerifyDictionaryEntry(node, "type", Value::Type::STRING))
     return nullptr;
 
   std::string type;
   node.GetString("type", &type);
   if (type == "ContentLayer")
     return InterpretContentLayer(node);
@@ skipping 32 matching lines @@
                  << "\n(" << error_message << ")";
     } else {
       LOG(ERROR) << path.LossyDisplayName()
                  << " doesn not encode a JSON dictionary.";
     }
     return nullptr;
   }
 
   return InterpretContentLayer(*root);
 }
-