Replace more for loops in GN

tools/gn/function_get_target_outputs.cc

 // Copyright 2014 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/build_settings.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/substitution_writer.h"
 #include "tools/gn/target.h"
@@ skipping 74 matching lines @@
 
   // Find the referenced target. The targets previously encountered in this
   // scope will have been stashed in the item collector (they'll be dispatched
   // when this file is done running) so we can look through them.
   const Target* target = NULL;
   Scope::ItemVector* collector = scope->GetItemCollector();
   if (!collector) {
     *err = Err(function, "No targets defined in this context.");
     return Value();
   }
-  for (size_t i = 0; i < collector->size(); i++) {
-    const Item* item = (*collector)[i]->get();
+  for (const auto& cur : *collector) {
+    const Item* item = cur->get();
     if (item->label() != label)
       continue;
 
     const Target* as_target = item->AsTarget();
     if (!as_target) {
       *err = Err(function, "Label does not refer to a target.",
           label.GetUserVisibleName(false) +
           "\nrefers to a " + item->GetItemTypeName());
       return Value();
     }
@@ skipping 18 matching lines @@
   } else {
     // Other types of targets are not supported.
     *err = Err(args[0], "Target is not an action, action_foreach, or copy.",
                "Only these target types are supported by get_target_outputs.");
     return Value();
   }
 
   // Convert to Values.
   Value ret(function, Value::LIST);
   ret.list_value().reserve(files.size());
-  for (size_t i = 0; i < files.size(); i++)
-    ret.list_value().push_back(Value(function, files[i].value()));
+  for (const auto& file : files)
+    ret.list_value().push_back(Value(function, file.value()));
 
   return ret;
 }
 
 }  // namespace functions