Replace more for loops in GN

tools/gn/input_file_manager.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/input_file_manager.h"
 
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/parser.h"
@@ skipping 237 matching lines @@
 
 int InputFileManager::GetInputFileCount() const {
   base::AutoLock lock(lock_);
   return static_cast<int>(input_files_.size());
 }
 
 void InputFileManager::GetAllPhysicalInputFileNames(
     std::vector<base::FilePath>* result) const {
   base::AutoLock lock(lock_);
   result->reserve(input_files_.size());
-  for (InputFileMap::const_iterator i = input_files_.begin();
-       i != input_files_.end(); ++i) {
-    if (!i->second->file.physical_name().empty())
-      result->push_back(i->second->file.physical_name());
+  for (const auto& file : input_files_) {
+    if (!file.second->file.physical_name().empty())
+      result->push_back(file.second->file.physical_name());
   }
 }
 
 void InputFileManager::BackgroundLoadFile(const LocationRange& origin,
                                           const BuildSettings* build_settings,
                                           const SourceFile& name,
                                           InputFile* file) {
   Err err;
   if (!LoadFile(origin, build_settings, name, file, &err))
     g_scheduler->FailWithError(err);
@@ skipping 41 matching lines @@
     if (data->completion_event)
       data->completion_event->Signal();
 
     callbacks.swap(data->scheduled_callbacks);
   }
 
   // Run pending invocations. Theoretically we could schedule each of these
   // separately to get some parallelism. But normally there will only be one
   // item in the list, so that's extra overhead and complexity for no gain.
   if (success) {
-    for (size_t i = 0; i < callbacks.size(); i++)
-      callbacks[i].Run(unowned_root);
+    for (const auto& cb : callbacks)
+      cb.Run(unowned_root);
   }
   return success;
 }