Convert //tools to use std::unique_ptr

tools/gn/builder.cc

 // Copyright (c) 2013 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 "tools/gn/builder.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "tools/gn/config.h"
@@ skipping 40 matching lines @@
 }
 
 }  // namespace
 
 Builder::Builder(Loader* loader) : loader_(loader) {
 }
 
 Builder::~Builder() {
 }
 
-void Builder::ItemDefined(scoped_ptr<Item> item) {
+void Builder::ItemDefined(std::unique_ptr<Item> item) {
   ScopedTrace trace(TraceItem::TRACE_DEFINE_TARGET, item->label());
   trace.SetToolchain(item->settings()->toolchain_label());
 
   BuilderRecord::ItemType type = BuilderRecord::TypeOfItem(item.get());
 
   Err err;
   BuilderRecord* record =
       GetOrCreateRecordOfType(item->label(), item->defined_from(), type, &err);
   if (!record) {
     g_scheduler->FailWithError(err);
@@ skipping 434 matching lines @@
   std::string ret;
   for (size_t i = 0; i < cycle.size(); i++) {
     ret += "  " + cycle[i]->label().GetUserVisibleName(false);
     if (i != cycle.size() - 1)
       ret += " ->";
     ret += "\n";
   }
 
   return ret;
 }