GN: Replace vector<ParseNode*> with vector<unique_ptr<ParseNode>> in parse_tree.h.

tools/gn/functions.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/functions.h"
 
 #include <stddef.h>
 #include <iostream>
 #include <utility>
 
@@ skipping 446 matching lines @@
     "      values = invoker.values\n"
     "    } else {\n"
     "      values = \"some default value\"\n"
     "    }\n"
     "  }\n";
 
 Value RunDefined(Scope* scope,
                  const FunctionCallNode* function,
                  const ListNode* args_list,
                  Err* err) {
-  const std::vector<const ParseNode*>& args_vector = args_list->contents();
+  const auto& args_vector = args_list->contents();
   if (args_vector.size() != 1) {
     *err = Err(function, "Wrong number of arguments to defined().",
                "Expecting exactly one.");
     return Value();
   }
 
   const IdentifierNode* identifier = args_vector[0]->AsIdentifier();
   if (identifier) {
     // Passed an identifier "defined(foo)".
     if (scope->GetValue(identifier->value().value()))
@@ skipping 443 matching lines @@
   }
 
   // Otherwise it's a no-block function.
   if (!VerifyNoBlockForFunctionCall(function, block, err))
     return Value();
   return found_function->second.no_block_runner(scope, function,
                                                 args.list_value(), err);
 }
 
 }  // namespace functions